Serum folic acid levels are associated with the presence and severity of liver steatosis in Chinese adults

Folic acid intervention ameliorates hepatic steatosis after long-term alcohol exposure by alleviating endoplasmic reticulum stress

In this study, the protective effect of folic acid on alcoholic fatty liver (AFL) was investigated. Eighty C57BL/6 J mice were assigned randomly to the saline control group, folic acid control group, ethanol model group, and folic acid + ethanol model group. After 10 weeks of intervention, folic acid intervention markedly decreased the liver index, serum ALT, serum TG, and hepatic TG levels. The HE and transmission electron microscopy revealed that folic acid intervention alleviated histopathological changes of hepatic steatosis. Western blot revealed that folic acid downregulated the protein levels of GRP78, p-PERK, p-eIF2α, p-IRE1α, XBP1, ATF6, SREBP-1c, FAS, and ACC. In conclusion, our findings demonstrated that folic acid intervention may relieve ethanol-induced ERs by inhibiting PERK-eIF2α, IRE1α-XBP1, and ATF6 signaling pathways, suggesting that folic acid may be a feasible preventive strategy for AFL.

DNA hypermethylation-induced suppression of ALKBH5 is required for folic acid to alleviate hepatic lipid deposition by enhancing autophagy in an ATG12-dependent manner

Nonalcoholic fatty liver disease (NAFLD) occurs when too much fat builds up in the liver. As a growing worldwide epidemic, NAFLD is strongly linked with multiple metabolic diseases including obesity, insulin resistance, and dyslipidemia. However, very few effective treatments are currently available. Folate, an essential B-group vitamin with important biological functions including DNA and RNA methylation regulation, has been shown to have a protective effect against NAFLD with its underlying mechanism remains largely unclear. Here, we show that administration of folic acid significantly improves glucose tolerance, insulin sensitivity, and dyslipidemia in high-fat diet (HFD) fed mice. Moreover, folic acid treatment significantly inhibits lipid deposition in hepatocytes both in vivo and in vitro. Mechanically, folic acid reduces the expression of m6A demethylase AlkB homolog 5 (ALKHB5) via promoter DNA hypermethylation. Decreased ALKBH5 causes increased m6A modification and increased expression of ATG12 in a demethylase activity-dependent manner, thereby promoting autophagy and preventing hepatic steatosis. Inhibition of ATG12 induced by overexpression of ALKBH5 could impair autophagy and the inhibitory effect of folic acid on lipid accumulation in hepatocytes. Together, these findings provide novel insights into understanding the protective role of folic acid in the treatment of NAFLD and suggest that folic acid may be a potential agent for combating NAFLD.

Unraveling folate deficiency: prevalence, biochemical associations, genetic determinants, and strategies for adolescent health in North India

BACKGROUND

Micronutrient deficiency is a global public health concern, especially among the adolescents of developing countries including India. Folate, an essential B-vitamin plays an indispensable role in various physiological processes throughout life. This is a cross-sectional study to determine prevalence of folate insufficiency among North-Indian school-going adolescents of various socio-economic backgrounds.

METHODS

A total of 3129 healthy school-going adolescents from North India were selected for the study and circulatory folate levels were measured using an electrochemiluminescence assay. Relationship of circulatory folate with various biochemical and anthropometric parameters were evaluated. Genetic determinants of folate levels in the study population were explored via both genome-wide and exome-wide association studies.

RESULTS

Our results indicate higher prevalence (41%) of folate insufficiency in urban adolescents attending government-funded schools, with distinct relationship of folate levels, biochemical parameters, and anthropometric traits with varied socioeconomic strata. Girls exhibited a higher percentage of folate insufficiency than their male contemporaries. Results from genome-wide association study indicate significant associations of MYO1B (p = 5.13 × 10-7), CDH9 (p = 5.36 × 10-7), and PANK3 (p = 6.66 × 10-7) genes with folate levels in adolescents. Single variant analysis from exome-wide association analysis reaffirms the association of a previously reported variant in MTHFR gene (rs1801133; p = 1.87 × 10-6) along with identification of novel missense variants in KRT7 (rs2608009; p = 2.16 × 10-6 and rs6580870; p = 9.49 × 10-6) and AK9 (rs1406957; p = 4.76 × 10-6) genes.

CONCLUSIONS

Our study highlights the importance of large-scale studies on prevalence of folate insufficiency and nutrigenomic regulation of folate levels in Indian population. Implementing multifaceted measures including food fortification, dietary diversification and health education in adolescents is crucial to combat folate deficiency in developing nations like India.

The association between weight-waist-adjustment index and serum folate in US adults: NHANES 2013 to 2018

Obesity is closely related to human metabolism and a variety of diseases. The association between weight-waist-adjustment index (WWI, a new index for obesity) and serum folate has not been sufficiently explored. Data from the National Health and Nutrition Examination Survey (2013-2018) was used to explore the correlation between WWI and serum folate. 12,757 adult participants were included in our study. In order to discern the relationship, we conducted weighted multiple linear regression analysis, generalized weighted smooth curve fitting and threshold effect analyses. Additionally, we executed subgroup analysis and interaction tests. There was a negative correlation between WWI and serum folate. In subgroup analysis, the relationship between WWI and serum folate were more pronounced among females, the elderly (65-80 years), nonsmokers, and those with hypertension or stroke. Furthermore, a nonlinear association between WWI and serum folate was found using smooth curve fitting (likelihood ratio = 0.014), with a threshold identified at WWI of 7.42. We discovered a stronger association between WWI and serum folate than other obesity markers including body mass index and waist circumference. Our study could help obese people predict serum folate and manage their nutrition well.

Association between vitamin A, E, and folate levels and risk of non-alcoholic fatty liver disease in adults with diabetes mellitus

Antioxidant vitamin deficiency may contribute to the development of metabolic diseases, such as non-alcoholic fatty liver disease (NAFLD). This study aimed to analyze the association between serum vitamin A, E, and folate levels and NAFLD in adults with diabetes mellitus. Using data from the Korean National Health and Nutrition Examination Survey (2016-2018), we conducted a cross-sectional analysis of adults over 19 with diabetes. NAFLD was identified through three prediction tools. Of 589 participants, 326, 445, and 527 had NAFLD according to the hepatic steatosis index, Framingham steatosis index (FSI), and comprehensive NAFLD score (CNS), respectively. Serum vitamin E levels were consistently higher in the NAFLD group across all diagnostic tools. Similarly, vitamin A levels were elevated in those with NAFLD as per the CNS. Folate levels were higher in the obese group according to the FSI. After adjusting for covariates, both vitamin A and E levels were positively associated with NAFLD. This suggests that higher serum levels of vitamins A and E may increase the risk of NAFLD in the Korean diabetic population. These findings highlight the importance of monitoring micronutrient levels in managing NAFLD in patients with diabetes.

Association of folate levels with all-cause and cause-specific mortality in patients with arthritis

OBJECTIVE

The purpose of this study was to examine the association of folate levels, including red blood cell (RBC) and serum folate with mortality (cardiovascular disease (CVD)-related, all-cause, and cancer-related) in patients with arthritis.

METHODS

We integrated and analyzed the data from the 1999-2018 National Health and Nutrition Examination Survey to conduct this study. Weighted Cox proportional hazard regression, restricted cubic spline (RCS) model, and subgroup analysis were used to analyze the association of RBC and serum folate levels with all-cause, cancer-related, and CVD-related mortality. Additionally, according to the folate levels quartiles, the differences in survival rate of RBC and serum folate with all-cause, cancer-related, and CVD-related mortality were showed in the Kaplan-Meier survival curves.

RESULTS

Our analysis included 12,332 individuals in total. The RCS showed the U-curve association of RBC and serum folate with CVD-related, all-cause, and cancer-related mortality in patients with arthritis. In addition, patients with arthritis in the highest quartile group of RBC and serum folate had the highest risk of CVD-related and all-cause mortality (all Log-rank P < 0.001).

CONCLUSIONS

RBC and serum folate concentrations are associated with U-shaped mortality (all-cause and CVD-related) in patients with arthritis in American, and maintaining an appropriate range of serum folate and RBC folate may promote public health. Key Points • Folate levels have U-shaped association with risk of mortality in patients with arthritis. • The potential mechanisms of folate levels in mortality of patients with arthritis need to be further explored.

Intermittent compared with continuous calorie restriction for treatment of metabolic dysfunction-associated steatotic liver disease: a randomized clinical trial

BACKGROUND

Calorie restriction has been demonstrated to be effective in treating metabolic dysfunction-associated steatotic liver disease (MASLD). However, it has been limited by poor long-term adherence.

OBJECTIVES

This study aimed to compare intermittent calorie restriction (ICR) with traditional continuous calorie restriction (CCR) for the treatment of MASLD.

METHODS

We conducted a 12-wk, parallel-arm, randomized controlled trial that included 60 adults with MASLD and abnormal glucose metabolism. The participants were randomly assigned to either the ICR group (2 successive days of fasting [∼500 kcal/d] and 5 d of recovery per week) or the CCR group. The primary outcome was liver fat content (LFC) measured by 1H-proton magnetic resonance spectroscopy. The secondary and exploratory outcomes included weight, body composition, glucose, insulin, lipids, and liver stiffness.

RESULTS

The mean reduction in LFC was -20.5% [95% confidence interval (CI): -25.0, -15.9%] in the ICR group and -15.5% (95% CI: -20.3, -10.8%) in the CCR group. Changes in LFC were not significantly different between the 2 groups (P = 0.15), and were homogeneous among different liver segments. The analysis of exploratory endpoints provided clues that the ICR was associated with greater reductions in fat mass and glycosylated hemoglobin. There were no significant differences in changes of weight, lean mass, insulin resistance, triglyceride, and liver stiffness between the 2 groups. Participants showed high adherence to both the ICR and CCR schemes.

CONCLUSIONS

The ICR and CCR schemes had similar effects on reducing LFC, suggesting that the ICR 5:2 diet can be an effective alternative for treating MASLD with high adherence.

TRIAL REGISTRATION NUMBER

This trial was registered at clinicaltrials.gov as NCT04283942.

Folic Acid as a Potential Vitamin in Glycemic Control: A Systematic Review

PURPOSE

This systematic review aims to examine the relationship between serum folate level and folic acid supplements with glycemic control parameters (fasting blood glucose (FBG), insulin level, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), and Hemoglobin A1C (HbA1c)) in adult individuals with current studies.

METHODS

In this study, which was designed as a systematic review, the searches were performed on Web of Science, Science Direct, Medline, Wiley, and Cochrane Library databases between April 10, 2023, and May 10, 2023, and the searches were updated between October 16, 2023, and November 14, 2023. Of the 1855 studies obtained from the screening, 17 met the criteria and were included in the systematic review. The PROSPERO system registered the study protocol (ID: CRD42023472434).

RECENT FINDINGS

Although no significant correlation was found between serum folate levels and glycemic control parameters in most of the cross-sectional studies included in this systematic review, most of the randomized controlled trials showed that glycemic control parameters (FBG, insulin, HOMA-IR) decreased significantly in the intervention group receiving folic acid supplementation compared to the control group. However, study durations were short, and HbA1c needed to be evaluated in most studies. This makes it difficult to get information about the long-term effects of folic acid supplementation. More comprehensive studies should be conducted to draw more precise conclusions about the relationship between folic acid levels and folic acid supplementation with glycemic control parameters.

Reorganization of 3D genome architecture provides insights into pathogenesis of early fatty liver disease in laying hens

BACKGROUND

Fatty liver disease causes huge economic losses in the poultry industry due to its high occurrence and lethality rate. Three-dimensional (3D) chromatin architecture takes part in disease processing by regulating transcriptional reprogramming. The study is carried out to investigate the alterations of hepatic 3D genome and H3K27ac profiling in early fatty liver (FLS) and reveal their effect on hepatic transcriptional reprogramming in laying hens.

RESULTS

Results show that FLS model is constructed with obvious phenotypes including hepatic visible lipid deposition as well as higher total triglyceride and cholesterol in serum. A/B compartment switching, topologically associating domain (TAD) and chromatin loop changes are identified by high-throughput/resolution chromosome conformation capture (HiC) technology. Targeted genes of these alternations in hepatic 3D genome organization significantly enrich pathways related to lipid metabolism and hepatic damage. H3K27ac differential peaks and differential expression genes (DEGs) identified through RNA-seq analysis are also enriched in these pathways. Notably, certain DEGs are found to correspond with changes in 3D chromatin structure and H3K27ac binding in their promoters. DNA motif analysis reveals that candidate transcription factors are implicated in regulating transcriptional reprogramming. Furthermore, disturbed folate metabolism is observed, as evidenced by lower folate levels and altered enzyme expression.

CONCLUSION

Our findings establish a link between transcriptional reprogramming changes and 3D chromatin structure variations during early FLS formation, which provides candidate transcription factors and folate as targets for FLS prevention or treatment.

Characteristics of changes in plasma proteome profiling after sleeve gastrectomy

Bariatric surgery (BS), recognized as the most effective intervention for morbid obesity and associated metabolic comorbidities, encompasses both weight loss-dependent and weight loss-independent mechanisms to exert its metabolic benefits. In this study, we employed plasma proteomics technology, a recently developed mass spectrometric approach, to quantitatively assess 632 circulating proteins in a longitudinal cohort of 9 individuals who underwent sleeve gastrectomy (SG). Through time series clustering and Gene Ontology (GO) enrichment analysis, we observed that complement activation, proteolysis, and negative regulation of triglyceride catabolic process were the primary biological processes enriched in down-regulated proteins. Conversely, up-regulated differentially expressed proteins (DEPs) were significantly associated with negative regulation of peptidase activity, fibrinolysis, keratinocyte migration, and acute-phase response. Notably, we identified seven proteins (ApoD, BCHE, CNDP1, AFM, ITIH3, SERPINF1, FCN3) that demonstrated significant alterations at 1-, 3-, and 6-month intervals post SG, compared to baseline. These proteins play essential roles in metabolism, immune and inflammatory responses, as well as oxidative stress. Consequently, they hold promising potential as therapeutic targets for combating obesity and its associated comorbidities.

Correlation of Nonalcoholic Fatty Liver Disease with Dietary Folate and Serum Folate in U.S. Adults: Cross-Sectional Analyses from National Health and Nutrition Examination Survey 2009-2018

Background and Aims: Nonalcoholic fatty liver disease (NAFLD) is a global health problem, and dietary intervention is still considered one of the primary interventions. This study aimed to examine cross-sectional associations between dietary and serum levels of folate and NAFLD. Methods: We conducted a study of 7543 adults who participated in the National Health and Nutrition Examination Survey, 2009-2018. NAFLD status was determined by a fatty liver index (FLI) value ≥60. Multivariable logistic regression models were used to estimate associations between folate and NAFLD. Results: Almost half (45%) of the patients were classified as having NAFLD based on the FLI. In the fully adjusted model, participants in the highest quartile of dietary total folate and food folate were found to have a lower prevalence of NAFLD than those in the lowest quartile [odds ratio (OR)quartile 4 versus 1 = 0.582; 95% confidence interval (CI) = 0.350-0.968; and ORquartile 4 versus 1 = 0.737; 95% CI = 0.611-0.888, respectively], and the fourth quartile values of serum total folate and 5-methyl-tetrahydrofolate were significantly negatively associated with NAFLD prevalence (ORquartile 4 versus 1 = 0.664; 95% CI = 0.495-0.891; and ORquartile 4 versus 1 = 0.712; 95% CI = 0.532-0.954, respectively). Subgroup analyses revealed that this beneficial association was more significant in women (ORquartile 4 versus 1 = 0.526; 95% CI = 0.329-0.843; pinteraction < 0.001) than in men (ORquartile 4 versus 1 = 0.805; 95% CI = 0.546-1.186). Conclusions: Higher dietary folate intake and serum folate levels are associated with a lower NAFLD prevalence among U.S. adults and the trend is more pronounced among women, indicating opportunities for dietary NAFLD interventions.

Association between use of vitamin and mineral supplement and non-alcoholic fatty liver disease in hypertensive adults

Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic metabolic disorder in hypertensive adults. Impaired metabolism of micronutrients may increase NAFLD risk by exacerbating oxidative stress, insulin resistance, and inflammation among hypertensive adults. In this first cross-sectional analysis of 7,376 hypertensive adults with 2,015 NAFLD cases in the Korea National Health and Nutrition Examination Survey, vitamin and mineral supplements (VMS) use was identified via questionnaire. NAFLD was defined by a hepatic steatosis index > 36. Multivariable-adjusted odds ratios (MVOR) and 95% confidence intervals (CIs) were calculated using logistic regression models. In our study, 18.6% were current users of VMS; of these, 76.7% used multi-vitamin/mineral supplements. Current VMS users had significantly lower odds of NAFLD, compared with non-users (MVOR [95% CI]: 0.73 [0.58-0.92]). The inverse association became attenuated and non-significant among those consuming VMS at higher frequency (≥ 2 times/day), for longer duration (> 16 months), and taking ≥ 2 VMS products. The inverse association with current use of VMS was only evident in those aged < 56 years (MVOR [95% CI]: 0.54 [0.40-0.72]) and men (MVOR [95% CI]: 0.56 [0.40-0.80])(Pinteraction ≤ 0.04). Our results suggest that VMS use may lower NAFLD risk, particularly among younger or male hypertensive adults, if taken in moderation.

Serum folate associated with nonalcoholic fatty liver disease and advanced hepatic fibrosis

The role played by serum folate in the progression of nonalcoholic fatty liver disease (NAFLD) remains controversial. The purpose of this study was to investigate the association of serum folate with NAFLD and advanced liver fibrosis (AHF). We conducted a cross-sectional study with 5417 participants using 2011-2018 NHANES data. Multiple logistic regression analysis and propensity score matching analysis were used to investigate the association of serum folate with NAFLD and AHF. In the completely adjusted model, participants in the high serum folate group had a 27% (OR 0.73, 95% CI 0.62, 0.87, p = 0.0003) and 53% (OR 0.47, 95% CI 0.35, 0.63, p < 0.0001) lower odds of suffering from NAFLD and AHF, respectively, compared to the low serum folate group. The similar results in propensity score matching further validated the above association. Stratified analysis showed that the negative correlation of serum folate with NAFLD and AHF demonstrated a broad consistency across populations. The results of this study indicate that higher serum folate level was associated with lower odds of NAFLD and AHF among US adults. Further prospective studies are necessary due to the limitations of cross-sectional studies.

Impaired Function of Solute Carrier Family 19 Leads to Low Folate Levels and Lipid Droplet Accumulation in Hepatocytes

Low serum folate levels are inversely related to metabolic associated fatty liver disease (MAFLD). The role of the folate transporter gene (SLC19A1) was assessed to clarify its involvement in lipid accumulation during the onset of MAFLD in humans and in liver cells by genomic, transcriptomic, and metabolomic techniques. Genotypes of 3 SNPs in a case-control cohort were initially correlated to clinical and serum MAFLD markers. Subsequently, the expression of 84 key genes in response to the loss of SLC19A1 was evaluated with the aid of an RT² profiler-array. After shRNA-silencing of SLC19A1 in THLE2 cells, folate and lipid levels were measured by ELISA and staining techniques, respectively. In addition, up to 482 amino acids and lipid metabolites were semi-quantified in SLC19A1-knockdown (KD) cells through ultra-high-performance liquid chromatography coupled with mass spectrometry. SNPs, rs1051266 and rs3788200, were significantly associated with the development of fatty liver for the single-marker allelic test. The minor alleles of these SNPs were associated with a 0.6/-1.67-fold decreased risk of developing MAFLD. When SLC19A1 was KD in THLE2 cells, intracellular folate content was four times lower than in wild-type cells. The lack of functional SLC19A1 provoked significant changes in the regulation of genes associated with lipid droplet accumulation within the cell and the onset of NAFLD. Metabolomic analyses showed a highly altered profile, where most of the species that accumulated in SLC19A1-KD-cells belong to the chemical groups of triacylglycerols, diacylglycerols, polyunsaturated fatty acids, and long chain, highly unsaturated cholesterol esters. In conclusion, the lack of SLC19A1 gene expression in hepatocytes affects the regulation of key genes for normal liver function, reduces intracellular folate levels, and impairs lipid metabolism, which entails lipid droplet accumulation in hepatocytes.

Association of serum folate with prevalence of non-alcoholic fatty liver disease among adults (NHANES 2011-2018)

Background

Folate was involved in oxidative stress, hepatic lipid metabolism and chronic hepatic inflammation. However, evidence about the association between serum folate level and non-alcoholic fatty liver disease (NAFLD) in general population is scarce. This study aimed to explore the relationship between serum folate level and NAFLD among adults.

Methods

7,146 adult participants aged 20 years and over who have complete data of serum folate level and liver function biomarkers in NHANES 2011-2018 were included. Serum folate level was measured by isotope-dilution high-performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). And suspected NAFLD was defined according to the United States fatty liver index (USFLI). Logistic regression and the restricted cubic spline models were performed.

Results

Serum folate level was inversely associated with the presence of NAFLD. When comparing the second, third and fourth quartiles of serum folate level to the lowest quartile, the adjusted ORs of the presence of NAFLD were 0.62 (0.49-0.78), 0.65 (0.51-0.84), and 0.43 (0.32-0.56) respectively (p for trend<0.001). The non-linear and L-shaped relationship was found between serum folate level and the presence of NAFLD in the restricted cubic spline regression (p for non-linearity <0.01). Consistent with serum total folate, serum 5-Methyltetrahydrofolate level was also inversely associated with the presence of NAFLD.

Conclusion

Higher serum folate level may be negatively associated with NAFLD.

Associations of different serum folate forms with indices of nonalcoholic fatty liver disease and advanced fibrosis

OBJECTIVE

We aim to examine the associations of different serum folate forms (total folate, 5-methyltetrahydrofolate [5-mTHF] and unmetabolized folic acid [UMFA]), with the prevalence of nonalcoholic fatty liver disease (NAFLD) and advanced fibrosis.

METHODS

This cross-sectional analysis was conducted in 6610 participants aged ≥ 18 years from the 2011-2018 National Health and Nutrition Examination Survey (NHANES) database. NAFLD was defined as a United States fatty liver index (USFLI) ≥ 30. Advanced fibrosis was defined as a Fibrosis-4 score (FIB-4) > 3.25, a NAFLD Fibrosis Score (NFS) > 0.676, and a Hepamet Fibrosis Score (HFS) ≥ 0.47, respectively.

RESULTS

The prevalence of NAFLD was 34.5%. Overall, serum total folate and 5-mTHF were inversely associated with the prevalence of NAFLD (both P for trend across quartiles <0.001). A similar trend was found for advanced fibrosis based on NFS and HFS (both P for trend across quartiles <0.05). However, a higher concentration of UMFA was significantly related to a higher prevalence of NAFLD (P for trend across quartiles =0.004). A similar relation was found for advanced fibrosis based on NFS (P for trend across quartiles =0.024).

CONCLUSIONS

Higher concentrations of serum total folate and 5-mTHF were associated with a lower prevalence of NAFLD and advanced fibrosis, while a higher concentration of UMFA was related to a higher prevalence of NAFLD.

Associations of serum folate and vitamin C levels with metabolic dysfunction-associated fatty liver disease in US adults: A nationwide cross-sectional study

Background

Clinical research results on the relationship between folate and non-alcoholic fatty liver disease are contradictory. Metabolic dysfunction-associated fatty liver disease (MAFLD) is a recently proposed concept. Evidence about the relationship between serum folate and MAFLD, especially considering the status of serum vitamin C, is scarce. This study was aimed to investigate the association of serum folate levels with the prevalence of MAFLD, and further to analyze the potential impact of serum vitamin C status on their association.

Methods

Totally 2,797 participants from National Health and Nutrition Examination Survey (NHANES) 2017-2018 were included. Vibration-controlled transient elastography was used to detect liver steatosis and fibrosis. Participants were divided in groups based on the tertiles of serum folate or vitamin C, and the serum folate or vitamin C level in T1 was low. Logistic regression analysis in the complex sample module was performed to illustrate the association of serum folate levels with the prevalence of MAFLD. Stratification analysis by serum vitamin C status was performed as well.

Results

Compared with the serum folate levels of T1 group, participants in the T3 group had 47.9% lower risk of MAFLD [OR = 0.521 (95% CI: 0.401-0.677)]. However, when participants were stratified by serum vitamin C levels, there was no association between the serum folate levels and MAFLD in the T1 or T2 group. Among participants in the T3 group of vitamin C status, participants in the T3 group of serum folate had a 63.6% lower risk of MAFLD compared with the T1 group [OR = 0.364 (95% CI: 0.147-0.903)].

Conclusions

High serum folate level is associated with lower prevalence of MAFLD, especially in participants with sufficient vitamin C.

Associations of serum multivitamin levels with the risk of non-alcoholic fatty liver disease: A population-based cross-sectional study in U.S. adults

Vitamins were closely associated with non-alcoholic fatty liver disease (NAFLD) development, but no study had explored the association of serum multivitamin levels with NAFLD risk. We assessed the association between serum levels of both single-vitamin and multivitamins (VA, VB6, VB9, VB12, VC, VD, and VE) and the risk of NAFLD, using the database of National Health and Nutrition Examination Survey (NHANES) (cycles 2003–2004 and 2005–2006). We employed multivariable logistic regression and weighted quantile sum (WQS) regression models to explore the association of serum multivitamin levels with NAFLD. Among all 2,294 participants, 969 participants with NAFLD were more likely to be male, older, less educated, or have hypertension/high cholesterol/diabetes. After adjustment of covariates, serum VC/VD/VB6/VB9 levels were negatively correlated with NAFLD risk, while serum VA/VE levels were positively correlated with NAFLD risk. In the WQS model, elevated serum VA/VE levels and lowered serum VC/VD/VB6 levels were linearly associated with increased NAFLD risk. There was a non-linear relationship between serum VB9/VB12 levels and NAFLD risk. There were evident associations between serum multivitamin levels and reduced NAFLD risk, which was mainly driven by VD/VB9/VC. In conclusion, our findings suggested that serum multivitamin levels were significantly associated with the risk of NAFLD.

The regulation of HBP1, SIRT1, and SREBP-1c genes and the related microRNAs in non-alcoholic fatty liver rats: The association with the folic acid anti-steatosis

Folic acid is one of the vital micronutrients that contribute to the genetic stability and other biological activities. In addition, microRNAs regulate gene expression through a multittude of pathways. Our current work aimd to explore the possible ameliorative potency of folic acid and its association with the hepatic miR-21, -34a, and -122 expression as well as their targeted genes, HBP1, SIRT1, and SREBP-1c in rats with non-alcoholic fatty liver disease (NAFL). A total of 50 Wistar rats were randomly divided into two groups, a control group (n = 10) and NAFL group (n = 40). Rats in NAFL group were fed a high-fat diet (HFD) containing 20% fats for 14 weeks. The NAFL group was further subdivided into four groups (n = 10/group), one untreated and three orally folic acid-treated groups (25, 50, and 75 μg/Kg b.wt). NAFL characteristics was evaluated in rats in addition to the miR-21, -34a, and -122 profile as well as the transcriptional levels of HBP1, SIRT1, and SREBP-1c genes. NAFL rats exhibited the classic traits of fatty liver disease profile and dysregulation in the pattern of miR-21, -34a, and -122 expression as well as their targeted genes (HBP1, SIRT1, and SREBP-1c, respectively) in the liver. Additionally, NAFL rats had altered levels of TNF-α and adiponectin. These alterations were significantly ameliorated in a dose-dependent pattern following the folic acid treatments. In conclusions, the anti-steatotic, insulin-sensitizing, glucose-lowering and lipotropic potencies of folic acid in NAFL rats may be linked to the epigenetic modulation of the hepatic microRNAs (miR-21, -34a, and -122) and the expression of their target genes (HBP1, SIRT1, and SREBP-1c).

Drug delivery strategy in hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, with high rates of recurrence and death. Surgical resection and ablation therapy have limited efficacy for patients with advanced HCC and poor liver function, so pharmacotherapy is the first-line option for those patients. Traditional antitumor drugs have the disadvantages of poor biological distribution and pharmacokinetics, poor target selectivity, high resistance, and high toxicity to nontargeted tissues. Recently, the development of nanotechnology has significantly improved drug delivery to tumor sites by changing the physical and biological characteristics of drugs and nanocarriers to improve their pharmacokinetics and biological distribution and to selectively accumulate cytotoxic agents at tumor sites. Here, we systematically review the tumor microenvironment of HCC and the recent application of nanotechnology in HCC.

Optimal Dietary Intake Composition of Choline and Betaine Is Associated with Minimized Visceral Obesity-Related Hepatic Steatosis in a Case-Control Study

Few studies on humans have comprehensively evaluated the intake composition of methyl-donor nutrients (MDNs: choline, betaine, and folate) in relation to visceral obesity (VOB)-related hepatic steatosis (HS), the hallmark of non-alcoholic fatty liver diseases. In this case-control study, we recruited 105 patients with HS and 104 without HS (controls). HS was diagnosed through ultrasound examination. VOB was measured using a whole-body analyzer. MDN intake was assessed using a validated quantitative food frequency questionnaire. After adjustment for multiple HS risk factors, total choline intake was the most significant dietary determinant of HS in patients with VOB (Beta: -0.41, p = 0.01). Low intake of choline (<6.9 mg/kg body weight), betaine (<3.1 mg/kg body weight), and folate (<8.8 μg/kg body weight) predicted increased odds ratios (ORs) of VOB-related HS (choline: OR: 22, 95% confidence interval [CI]: 6.5-80; betaine: OR: 14, 95% CI: 4.4-50; and folate: OR: 19, 95% CI: 5.2-74). Combined high intake of choline and betaine, but not folate, was associated with an 81% reduction in VOB-related HS (OR: 0.19, 95% CI: 0.05-0.69). Our data suggest that the optimal intake of choline and betaine can minimize the risk of VOB-related HS in a threshold-dependent manner.

Effect of green-Mediterranean diet on intrahepatic fat: the DIRECT PLUS randomised controlled trial

OBJECTIVE

To examine the effectiveness of green-Mediterranean (MED) diet, further restricted in red/processed meat, and enriched with green plants and polyphenols on non-alcoholic fatty liver disease (NAFLD), reflected by intrahepatic fat (IHF) loss.

DESIGN

For the DIRECT-PLUS 18-month randomized clinical trial, we assigned 294 participants with abdominal obesity/dyslipidaemia into healthy dietary guidelines (HDG), MED and green-MED weight-loss diet groups, all accompanied by physical activity. Both isocaloric MED groups consumed 28 g/day walnuts (+440 mg/day polyphenols provided). The green-MED group further consumed green tea (3-4 cups/day) and Mankai (a Wolffia globosa aquatic plant strain; 100 g/day frozen cubes) green shake (+1240 mg/day total polyphenols provided). IHF% 18-month changes were quantified continuously by proton magnetic resonance spectroscopy (MRS).

RESULTS

Participants (age=51 years; 88% men; body mass index=31.3 kg/m²; median IHF%=6.6%; mean=10.2%; 62% with NAFLD) had 89.8% 18-month retention-rate, and 78% had eligible follow-up MRS. Overall, NAFLD prevalence declined to: 54.8% (HDG), 47.9% (MED) and 31.5% (green-MED), p=0.012 between groups. Despite similar moderate weight-loss in both MED groups, green-MED group achieved almost double IHF% loss (-38.9% proportionally), as compared with MED (-19.6% proportionally; p=0.035 weight loss adjusted) and HDG (-12.2% proportionally; p<0.001). After 18 months, both MED groups had significantly higher total plasma polyphenol levels versus HDG, with higher detection of Naringenin and 2-5-dihydroxybenzoic-acid in green-MED. Greater IHF% loss was independently associated with increased Mankai and walnuts intake, decreased red/processed meat consumption, improved serum folate and adipokines/lipids biomarkers, changes in microbiome composition (beta-diversity) and specific bacteria (p<0.05 for all).

CONCLUSION

The new suggested strategy of green-Mediterranean diet, amplified with green plant-based proteins/polyphenols as Mankai, green tea, and walnuts, and restricted in red/processed meat can double IHF loss than other healthy nutritional strategies and reduce NAFLD in half.

TRIAL REGISTRATION NUMBER

NCT03020186.

The relationship between serum folate and grip strength in American adults

We used data from NHANES to explore the associations between serum folate and grip strength, and found that high levels of serum folate were associated with increased grip strength among females rather than males. It is recommended to maintain a proper level of serum folate, especially in women.

PURPOSE

Associations and dose-response relationships between serum total folate, 5-methyltetrahydrofolate, and grip strength in general adults were unknown. Thus, we conducted this analysis for further exploration.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) database of 2011-2014 cycle were used. The independent variables including serum total folate, combined total folate (total folate plus Mefox), and 5-methyltetrahydrofolate. The dependent variable was BMI-corrected grip strength. Linear regression and the restricted cubic splines were used in our analyses.

RESULTS

A total of 9079 adults aged over 20 years were included. In multivariate-adjusted model 2, compared with quartile (Q) 1, grip strength increased in Q3 of combined total folate and total folate, and the weighted β values with 95% confidence intervals (CIs) of grip strength were 0.06 (0.01, 0.12) and 0.06 (0.00, 0.10) for combined total folate and total folate, respectively. In the stratified analysis by gender, positive relationships between combined total folate, total folate, and 5-methyltetrahydrofolate and grip strength were found only in females, with β (95% CIs) of 0.07 (0.02, 0.12), 0.07 (0.03, 0.12), and 0.09 (0.05, 0.13) for combined total folate, total folate, and 5-methyltetrahydrofolate in Q4, respectively. Non-linear positive dose-response relationships between serum folate and grip strength were also found only in females, not in males.

CONCLUSION

Our study suggested a positive association between serum folate and grip strength, while this positive association was only found in females; besides, the dose-response relationships were in a non-linear trend. Thus, it is recommended to maintain a proper serum folate level to keep better muscle strength, especially for women.

Investigating the effects of a novel rumen-protected folic acid supplement on feedlot performance and carcass characteristics of beef steers

Angus-crossbred steers (n = 180; 292 ± 18 kg) from a single ranch were used to investigate the effects of a novel rumen-protected folic acid (RPFA) supplement on feedlot performance and carcass characteristics. On d 0, steers were blocked by body weight to pens (5 steers/pen), and pens within a block were randomly assigned to dietary treatments (n = 6 pens/treatment): target intake of 0 (CON), 30 (RPFA-30), 60 (RPFA-60), 90 (RPFA-90), 120 (RPFA-120), or 150 (RPFA-150) mg RPFA·steer⁻¹·d⁻¹. Steers were weighed before feeding on d −1, 0, 55, 56, 86, 87, 181, and 182. Pen average daily gain (ADG), dry matter intake (DMI), and gain:feed (G:F) were calculated for growing (d 0 to 56), dietary transition (d 56 to 87), finishing (d 87 to 182), and overall (d 0 to 182). Liver and blood samples were collected from two steers/pen before trial initiation and at the end of growing and finishing. Steers were slaughtered on d 183, and carcass data were collected after a 48-h chill. Data were analyzed as a randomized complete block design using ProcMixed of SAS 9.4 (fixed effects of treatment and block; experimental unit of pen). Liver abscess scores were analyzed using the Genmod Procedure of SAS 9.4. Contrast statements assessed the polynomial effects of RPFA. Supplemental RPFA linearly increased plasma folate at the end of growing and finishing (P < 0.01), and linearly decreased plasma glucose at the end of growing (P = 0.01). There was a cubic effect of RPFA on liver folate at the end of growing (P = 0.01), driven by lesser concentrations for RPFA-30, RPFA-60, and RPFA-150. Growing period ADG and G:F were greatest for CON and RPFA-120 (cubic P ≤ 0.03). Transition period DMI was linearly increased due to RPFA (P = 0.05). There was a tendency for a cubic effect of RPFA on the percentage of livers with no abscesses (P = 0.06), driven by a greater percentage of non-abscessed livers in RPFA-30 and RPFA-60. Despite supplementing 1 mg Co/kg DM, and regardless of treatment, plasma vitamin B12 concentrations were low (<200 pg/mL), which may have influenced the response to RPFA as vitamin B12 is essential for recycling of folate.

Osteocalcin and Non-Alcoholic Fatty Liver Disease: Lessons From Two Population-Based Cohorts and Animal Models

Osteocalcin regulates energy metabolism in an active undercarboxylated/uncarboxylated form. However, its role on the development of non-alcoholic fatty liver disease (NAFLD) is still controversial. In the current study, we investigated the causal relationship of circulating osteocalcin with NAFLD in two human cohorts and studied the effect of uncarboxylated osteocalcin on liver lipid metabolism through animal models. We analyzed the correlations of serum total/uncarboxylated osteocalcin with liver steatosis/fibrosis in a liver biopsy cohort of 196 participants, and the causal relationship between serum osteocalcin and the incidence/remission of NAFLD in a prospective community cohort of 2055 subjects from Shanghai Changfeng Study. Serum total osteocalcin was positively correlated with uncarboxylated osteocalcin (r = 0.528, p < .001). Total and uncarboxylated osteocalcin quartiles were inversely associated with liver steatosis, inflammation, ballooning, and fibrosis grades in both male and female participants (all p for trend <.05). After adjustment for confounding glucose, lipid, and bone metabolism parameters, the male and female participants with lowest quartile of osteocalcin still had more severe liver steatosis, with multivariate-adjusted odds ratios (ORs) of 7.25 (1.07-49.30) and 4.44 (1.01-19.41), respectively. In the prospective community cohort, after a median of 4.2-year follow-up, the female but not male participants with lowest quartile of osteocalcin at baseline had higher risk to develop NAFLD (hazard ratio [HR] = 1.90; 95% confidence interval [CI] 1.14-3.16) and lower chance to achieve NAFLD remission (HR = 0.56; 95% CI 0.31-1.00). In wild-type mice fed a Western diet, osteocalcin treatment alleviated hepatic steatosis and reduced hepatic SREBP-1 and its downstream proteins expression. In mice treated with osteocalcin for a short term, hepatic SREBP-1 expression was decreased without changes of glucose level or insulin sensitivity. When SREBP-1c was stably expressed in a human SREBP-1c transgenic rat model, the reduction of lipogenesis induced by osteocalcin treatment was abolished. In conclusion, circulating osteocalcin was inversely associated with NAFLD. Osteocalcin reduces liver lipogenesis via decreasing SREBP-1c expression. © 2020 American Society for Bone and Mineral Research (ASBMR).

Folic Acid Affects Iron Status in Female Rats with Deficiency of These Micronutrients

Although simultaneous supplementation with iron and folic acid is justified, the potential interactions between these micronutrients are unknown. The aim of this study was to determine the effects of oral iron and folic acid, administered together or separately, on iron concentration in tissues in rats with a deficiency of both these micronutrients. In the first stage of the experiment (28 days), 150 8-week-old female Wistar rats were randomly assigned to a control group (C; n = 30) fed the standard diet and to a study group (n = 120) fed a diet deficit in iron and folate. The study group was then randomly divided to four groups: D group fed a deficit diet, FE group fed a deficit diet with iron gluconate, the FOL group fed a deficit diet with folate acid, and the FEFOL group fed a deficit diet with iron gluconate and folate acid. After 2, 10, and 21 days of supplementation, ten animals from each group were killed. Morphological parameters were measured in whole blood. Iron concentration was assayed in serum, liver, spleen, pancreas, heart, and kidneys. Folic acid supplementation more significantly decreased iron concentrations in the pancreas and spleen than in the D group after 10 and 21 days of supplementation. Moreover, the combination of iron with folic acid markedly decreased iron levels in the liver and spleen, in comparison with iron alone, after 10 and 21 days of the experiment. In conclusion, folic acid affects iron status in female rats deficient in these micronutrients in moderate and long-term supplementation.

Folic acid attenuates high-fat diet-induced steatohepatitis via deacetylase SIRT1-dependent restoration of PPARα

BACKGROUND

Folic acid has been shown to improve non-alcoholic steatohepatitis (NASH), but its roles in hepatic lipid metabolism, hepatic one-carbon metabolism, and gut microbiota are still unknown.

AIM

To demonstrate the role of folic acid in lipid metabolism and gut microbiota in NASH.

METHODS

Twenty-four Sprague-Dawley rats were assigned into three groups: Chow diet, high-fat diet (HFD), and HFD with folic acid administration. At the end of 16 wk, the liver histology, the expression of hepatic genes related to lipid metabolism, one-carbon metabolism, and gut microbiota structure analysis of fecal samples based on 16S rRNA sequencing were measured to evaluate the effect of folic acid. Palmitic acid-exposed Huh7 cell line was used to evaluate the role of folic acid in hepatic lipid metabolism.

RESULTS

Folic acid treatment attenuated steatosis, lobular inflammation, and hepatocellular ballooning in rats with HFD-induced steatohepatitis. Genes related to lipid de novo lipogenesis, β-oxidation, and lipid uptake were improved in HFD-fed folic acid-treated rats. Furthermore, peroxisome proliferator-activated receptor alpha (PPARα) and silence information regulation factor 1 (SIRT1) were restored by folic acid in HFD-fed rats and palmitic acid-exposed Huh7 cell line. The restoration of PPARα by folic acid was blocked after transfection with SIRT1 siRNA in the Huh7 cell line. Additionally, folic acid administration ameliorated depleted hepatic one-carbon metabolism and restored the diversity of the gut microbiota in rats with HFD-induced steatohepatitis.

CONCLUSION

Folic acid improves hepatic lipid metabolism by upregulating PPARα levels via a SIRT1-dependent mechanism and restores hepatic one-carbon metabolism and diversity of gut microbiota, thereby attenuating HFD-induced NASH in rats.

One-Carbon Metabolism and Nonalcoholic Fatty Liver Disease: The Crosstalk between Nutrients, Microbiota, and Genetics

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide. Its etiology includes nutritional, genetic, and lifestyle factors. Several mechanisms may link one-carbon metabolism - the associated metabolic pathways of folate, methionine, and choline - to the onset of NAFLD. In this review, we attempted to assess how choline, folate, methionine, and betaine affect NAFLD development, mainly through their role in the secretion of very low-density lipoproteins (VLDL) from the liver. We also reviewed recent articles that have described the relation between microbiota metabolism and NAFLD progression. Moreover, we describe the effect of single-nucleotide polymorphisms (SNP) in genes related to one-carbon metabolism and disease prevalence. We additionally seek SNP identified by genome-wide associations that may increase the risk of this disease. Even though the evidence available is not entirely consistent, it seems that the concentrations of choline, methionine, folate, and betaine may affect the progression of NAFLD. Since there is no effective therapy for NAFLD, further investigations into the link between nutrition, gut microbiota, genetic factors, and NAFLD are still necessary, with a particular emphasis on methyl donors.

Effect of folate supplementation on immunological and autophagy markers in experimental nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Chronic hepatic inflammation is an important pathogenic mediator of nonalcoholic fatty liver disease (NAFLD) that contributes to disease severity. It is commonly suggested that autophagy dysfunction may be an underlying cause of nonalcoholic fatty liver disease. However, the exact role of autophagy in lipid metabolism remains controversial. There has been a growing interest in the role of folate supplementation for the treatment and/or prevention of NAFLD. We aimed in this study to investigate the effects of different doses of folate supplementation on several immune markers and autophagy trying to explore the complex role of IL-22 and autophagy in NAFLD.

METHODS

Fifty Wistar rats were randomly separated into experimental (n = 40) and control groups (n = 10), which were fed for eight weeks with a high-fat diet (HFD) containing 40% fats or a standard diet, respectively. The experimental group was further subdivided into four subgroups where the first subgroup was left untreated while the other three were treated with different doses of folate (50, 100, and 150 μg/kg of body weight, respectively). At the end of the experimental period, animals from each group were sacrificed for blood and tissue analyses.

RESULTS

NAFLD rats showed decreased IL-22 serum levels and increased LC3B expression as compared to controls. Folate treatment was significantly associated with improvement in disease parameters, reduced presence of the pro-inflammatory cytokines TNF-α and CXCL8 and LC3B expression, and increased IL-22 levels in a dose-dependent manner.

CONCLUSION

These results highlight the capacity of folate to modulate the production of several pro-inflammatory cytokines and autophagy thereby having a favorable impact disease progression.

Folic Acid Reduced Triglycerides Deposition in Primary Chicken Hepatocytes

Abdominal fat or fatty liver cause huge economic losses in the poultry industry, and nonalcoholic fatty liver disease (NAFLD) is also a global health issue in humans. More than 90% of de novo lipogenesis in humans and chickens is undertaken by the liver, which is proved to be full of lipids in new-born chickens. Folic acid was thought to have correlation with lipid metabolism. Primary hepatocytes from new-born chickens were employed as a natural model of early stage fatty liver in vitro and further to explore whether folic acid could prevent fatty liver in the current study. We found that folic acid addition reduced triglyceride deposition by suppressing de novo fatty acid synthesis and coordinately promoting triglyceride hydrolysis and exportation in primary chicken hepatocytes from new-born chickens. In addition, lipogenesis suppression was through the PI3K/AKT/SREBP pathway mediated by weakening insulin/IGF signal. Our data suggested that folic acid may be considered as a precautionary strategy for abdominal fat deposition in broilers or fatty liver in laying hens and humans. In addition, mechanism regulation also implied that an IGF2 inhibitor and PI3K inhibitor may be used for the NAFLD precautionary measure to reduce TG deposition.

High-fat diet consumption reduces hepatic folate transporter expression via nuclear respiratory factor-1

Folate is an essential micronutrient for biological function. The liver, a primary organ for folate metabolism and storage, plays an important role in folate homeostasis. Proton-coupled folate transporter (PCFT) and reduced folate carrier (RFC) are the major folate transporters responsible for folate uptake at basolateral membrane of hepatocytes. Low serum folate levels are frequently associated with obesity. We investigated the mechanism that regulated folate status in a mouse model with diet-induced obesity. Mice (C57BL/6J) were fed a high-fat diet (60% kcal fat) for 8 weeks. Mice displayed increased hepatic lipid accumulation and decreased folate levels in the liver and serum compared to mice fed a normal chow diet (10% kcal fat). High-fat diet-fed mice had low expression of PCFT and RFC and decreased nuclear respiratory factor-1 (NRF-1)/DNA-binding activity. Treatment with NRF-1 siRNA or palmitic acid reduced folate transporter expression in hepatocytes. Inhibition of NRF-1 mediated folate transporter expression significantly reduced intracellular folate levels. These results suggest that chronic consumption of high-fat diets impairs folate transporter expression via NRF-1-dependent mechanism, leading to reduced hepatic folate storage. Understanding the regulation of folate homeostasis in obesity may have an important implication in current guideline of folate intake. KEY MESSAGES: Serum and liver folate levels are decreased in diet-induced obese mice. Chronic high-fat diet consumption impairs expression of hepatic PCFT and RFC. NRF-1 regulates hepatic folate transporters expression and folate levels.

Folate and B12 Levels Correlate with Histological Severity in NASH Patients

BACKGROUND

The correlation between abnormal vitamin serum levels and chronic liver disease has been previously described in literature. However, the association between the severity of folate serum levels (B9), vitamin B12 and nonalcoholic steatohepatitis (NASH) has not been widely evaluated. Therefore, the aim of this study was to investigate the existence of such a correlation in a cohort of NASH patients.

METHODS

All patients aged 18 years and older who were diagnosed with biopsy-proven NASH at the EMMS hospital in Nazareth during the years 2015-2017 were enrolled in this study. Data regarding demographic, clinical and laboratory parameters was collected. Patients with other liver diseases were excluded.

RESULTS

Eighty-three NASH patients were enrolled during the study period. The mean age was 41 ± 11 years and the majority of patients were male. Mean values of folate and B12 were 9.85 ± 10.90 ng/mL and 387.53 ± 205.50 pg/mL, respectively. Half of the patients were presented with a grade 1 steatosis (43.4%), a grade 2 fibrosis (50.6%) and a grade 3 activity score (55.4%). The fibrosis grade was significantly correlated with low folate levels on multivariate analysis (p-value < 0.01). Similarly, low B12 levels were significantly associated with a higher fibrosis grade and NASH activity (p-value < 0.001 and p-value < 0.05 respectively).

CONCLUSION

Our study demonstrated a statistically significant correlation between low levels of folate and vitamin B12 with the histological severity of NASH. These findings could have diagnostic and therapeutic implications for patient management and follow-up.

An Integrated Understanding of the Rapid Metabolic Benefits of a Carbohydrate-Restricted Diet on Hepatic Steatosis in Humans

A carbohydrate-restricted diet is a widely recommended intervention for non-alcoholic fatty liver disease (NAFLD), but a systematic perspective on the multiple benefits of this diet is lacking. Here, we performed a short-term intervention with an isocaloric low-carbohydrate diet with increased protein content in obese subjects with NAFLD and characterized the resulting alterations in metabolism and the gut microbiota using a multi-omics approach. We observed rapid and dramatic reductions of liver fat and other cardiometabolic risk factors paralleled by (1) marked decreases in hepatic de novo lipogenesis; (2) large increases in serum β-hydroxybutyrate concentrations, reflecting increased mitochondrial β-oxidation; and (3) rapid increases in folate-producing Streptococcus and serum folate concentrations. Liver transcriptomic analysis on biopsy samples from a second cohort revealed downregulation of the fatty acid synthesis pathway and upregulation of folate-mediated one-carbon metabolism and fatty acid oxidation pathways. Our results highlight the potential of exploring diet-microbiota interactions for treating NAFLD.