Dietary folic acid addition reduces abdominal fat deposition mediated by alterations in gut microbiota and SCFA production in broilers

Folic acid supplementation prevents high body fat-induced bone loss through TGR5 signaling pathways

Osteoporosis caused by bone loss is one of the serious global public health problems. Folic acid is a B vitamin with multiple physiological functions such as lipid regulation and antioxidant capacity, and its potential to improve bone loss has attracted our attention. Through NHANES database analysis, we found that folic acid intake was significantly correlated with whole-body bone mineral density (BMD) in people aged 20-60 years, and the association may be mediated by the body fat rate. Male C57Bl/6 mice were fed either a normal diet or a high-fat diet, and folic acid was added to drinking water for supplementation. Our results indicated that mice with high body fat showed bone microstructure damage and bone loss, while folic acid supplementation improved bone quality. At the same time, we found that mice with high body fat exhibited abnormal blood lipids, dysregulation of intestinal flora, and metabolic disorders. Folic acid supplementation improved these phenomena. Through the network analysis of intestinal flora and metabolites, we found that LCA and TGR5 may play important roles. The results showed that folic acid promoted the expression of LCA and TGR5 in mice, increased the phosphorylation of AMPK, and decreased the phosphorylation of NF-κB and ERK, thereby reducing bone loss. In summary, folic acid intake is closely related to BMD, and folic acid supplementation can prevent high body fat-induced bone loss. Our study provides new ideas and an experimental basis for preventing bone loss and osteoporosis.

The Changes in Fecal Bacterial Communities in Goats Offered Rumen-Protected Fat

Leizhou goats are famous for their delicious meat but have inferior growth performance. There is little information on rumen-protected fat (RPF) from the Leizhou goat. Hence, we observed the effects of RPF on growth, fecal short-chain fatty acids, and bacteria community with respect to Leizhou goats. Twelve goats (13.34 ± 0.024 kg) were selected and assigned randomly to one of two treatments: (1) a control diet (CON) and (2) 2.4% RPF with a control diet (RPF). The final body weight and average daily gain (ADG) were greater (p < 0.05), and the dry matter intake (DMI): ADG was lower (p < 0.05) in the RPF group than in the CON group. There were no differences in DMI between the CON and RPF groups. The concentrations of total short-chain fatty acids, acetate, propionate, and butyrate were lower (p < 0.05) in the RPF group than in the CON group. The relative abundances of Ruminococcus, Rikenellaceae_RC9_gut_group, Treponema, norank_f__norank_o__RF39, Eubacterium_siraeum_group, and Ruminococcus_torques_group were lower (p < 0.05) in the RPF group than in the CON group. The relative abundances of Bacteroides, norank_f__norank_o__Clostridia_UCG-014, norank_f__Eubacterium_coprostanoligenes_group, Eubacterium_ruminantium_group, norank_f__Oscillospirale-UCG-010, Oscillospiraceae_UCG-002, and Family_XIII_AD3011_group were greater (p < 0.05) in the RPF group than in the CON group. It was concluded that RPF could improve the goats' growth performance by regulating their fecal bacteria communities.

Homicide or Happiness: Did Folate Fortification and Public Health Campaigns Influence Homicide Rates and the Great American Crime Decline?

The last several years have witnessed a remarkable growth in research directed at nutrition and behavior, with increased interest in the field of nutritional criminology. It is becoming clear that dietary patterns and specific nutrients play an important role in cognition and behavior, including those related to aggression, violence, and antisocial activity. Included in this expanding knowledge base is the recognition that folate, through multiple pathways, including enzymatic reactions and gut microbiome ecology, plays a critical role in central nervous system functioning. These mechanistic advances allow for a retrospective analysis of a topic that remains unexplained-the sudden and unpredicted drop in homicide and other violent crime rates in the United States and other nations in the 1990s. Here, we revisit this marked reduction in homicide rates through the lens of the coincident public health campaign (and subsequent mandatory fortification) to increase folic acid intake. Based on objectively measured blood folate levels through the National Health and Nutrition Examination Surveys, there is little doubt that tissue folate witnessed a dramatic rise at the national level from 1988 through 2000. Drawing from accumulated and emerging research on the neurobehavioral aspects of folate, it is our contention that this relatively sudden and massive increase in tissue folate levels may have contributed to reductions in violent crime in the United States.

Fecal microbiota transplantation revealed the function of folic acid on reducing abdominal fat deposition in broiler chickens mediated by gut microbiota

Excess abdominal fat reduces carcass yield and feed conversion ratio, thereby resulting in significant economic losses in the poultry industry. Our previous study demonstrated that dietary addition of folic acid reduced fat deposition and changed gut microbiota and short-chain fatty acid. However, whether folic acid regulating abdominal fat deposition was mediated by gut microbiota was unclear. A total of 210 one-day-old broiler chickens were divided into 3 groups including the control (CON), folic acid (FA), and fecal microbiota transplantation (FMT) groups. From 14th day, broiler chickens in CON and FA groups were given perfusion administration with 1 mL diluent daily, while 1 mL fecal microbiota transplantation suspension from FA group prepared before was perfusion in FMT group receiving control diets. The result showed that abdominal fat percentage was significantly lower in FA and FMT groups when compared with CON group (P < 0.05). Morphology analysis revealed that the villus height of jejunum and ileum were significantly higher in FMT group (P < 0.05), and the villus height of jejunum was also significantly higher in FA group (P < 0.05), while the diameter and cross-sectional area (CSA) of adipocytes were significantly decreased in FA and FMT groups when compared with CON group (P < 0.05). Western blot results indicated that the expression levels of FOXO1 and PLIN1 in FMT group were significantly increased (P < 0.05), whereas the expression levels of PPARγ, C/EBPα, and FABP4 were significantly decreased (P < 0.05). Additionally, the Chao1, Observed-species, Shannon and Simpson indexes in FA and FMT groups were significantly higher (P < 0.05), but the microbiota were similar between FMT and FA groups (P < 0.05). LEfSe analysis determined that Lactobacillus, Clostridium and Dehalobacterium were found to be predominant in FA group, while Oscillospira, Shigella, and Streptococcus were the dominant microflora in FMT group. Furthermore, these cecal microbiota were mostly involved in infectious disease, cellular community prokaryotes, cell motility and signal transduction in FA group (P < 0.05), whereas functional capacities involved in signal transduction, cell motility, infectious disease and environment adaptation were enriched significantly of cecal microbiota in FMT group (P < 0.05). In summary, both fecal microbiota transplantation from the broiler chickens of dietary added folic acid and dietary folic acid addition effectively reduced abdominal fat deposition, indicating that the regulatory effect of folic acid on abdominal fat deposition was mediated partly by gut microbiota in broiler chickens.

Microbiota-accessible fiber activates short-chain fatty acid and bile acid metabolism to improve intestinal mucus barrier in broiler chickens

IMPORTANCE

The intestinal mucus barrier, located at the interface of the intestinal epithelium and the microbiota, is the first line of defense against pathogenic microorganisms and environmental antigens. Dietary polysaccharides, which act as microbiota-accessible fiber, play a key role in the regulation of intestinal microbial communities. However, the mechanism via which dietary fiber affects the intestinal mucus barrier through targeted regulation of the gut microbiota is not clear. This study provides fundamental evidence for the benefits of dietary fiber supplementation in broiler chickens through improvement in the intestinal mucus barrier by targeted regulation of the gut ecosystem. Our findings suggest that the microbiota-accessible fiber-gut microbiota-short-chain fatty acid/bile acid axis plays a key role in regulating intestinal function.

Gut microbiota bridges dietary nutrients and host immunity

Dietary nutrients and the gut microbiota are increasingly recognized to cross-regulate and entrain each other, and thus affect host health and immune-mediated diseases. Here, we systematically review the current understanding linking dietary nutrients to gut microbiota-host immune interactions, emphasizing how this axis might influence host immunity in health and diseases. Of relevance, we highlight that the implications of gut microbiota-targeted dietary intervention could be harnessed in orchestrating a spectrum of immune-associated diseases.

Age-associated changes in the growth development of abdominal fat and their correlations with cecal gut microbiota in broiler chickens

Excess abdominal fat is a common phenomenon in broiler chickens. Gut microbiota could regulate lipid metabolism through their effects on short-chain fatty acids (SCFAs) production. This study was conducted to investigate the potential relationship between abdominal fat development and cecal microorganism populations. Abdominal fat and cecum contents were collected at 3, 7, 14, 21, 28, 35, and 42 d of age. The results showed that abdominal fat weight increased with age. The abdominal fat percentage was higher between 7 and 21 d of age than at 3 d (P < 0.05), and it increased again at 28 to 42 d (P < 0.05). Morphological analysis showed that adipocyte diameter and cross-sectional area (CSA) increased significantly after 14 d of age (P < 0.05). Moreover, gut microbiota analysis indicated that the Chao1 and Shannon indices were higher between 14 and 28 d than at 3 d of age (P < 0.05). Furthermore, LEfse analysis revealed that Faecalibacterium, Anaerotruncus, Anaeroplasma, Subdoligranulum, and Clostridium emerged to become dominant at 14 d. A greater abundance of Bacteroides, Ruminococcus, Dehalobacterium, and Lactobacillus were determined at 28 d when compared with 14 d of age. Parabacteroides, Ochrobactrum, Lactobacillus, Blautia, Alistipes, Dehalobacterium, Odoribacter, and Suuterella were found to be predominant at 42 d. PICRUSt analysis revealed that amino acid metabolism, lipid metabolism, and terpenoids and polyketides metabolism were elevated at 14 d; the immune and digestive systems were significantly developed at 28 d. In addition, cecum propionic acid and butyric acid contents gradually increased (P < 0.05), while the isobutyric acid contents gradually decreased with advancing age (P < 0.05). Correlation analysis among SCFAs, differential genera and abdominal fat suggested that Coprobacillus, Shigella, and Butyricicoccus had negative correlations with propionic acid, butyric acid, and abdominal fat weight, but positive correlations with isobutyric acid. Isobutyric acid was identified as being negatively associated with abdominal fat weight, while the reverse was found for propionic acid and butyric acid. In conclusion, abdominal fat development is correlated with the emergence of specific microbes and d 14 may be a pivotal age for establishing this relationship.

Evaluation of dynamic effects of dietary medium-chain monoglycerides on performance, intestinal development and gut microbiota of broilers in large-scale production

Medium-chain monoglycerides (MG) have been reported to affect the productive performance, gut microbiota and health of broiler chickens reared in ideal experimental conditions at home and abroad. However, the effects of MG on performance, intestinal development and gut microbiota of chickens in large-scale farms during different feed stages remain unknown. The present study was conducted on a modern farm with a total of 12,000 yellow feathered broiler chicks that were randomly allotted to 2 groups (1000 chicks/replicate, 6 replicates/group) for a 70-day trial. The control group (CON group) received a basal diet, and the treated group (MG group) was fed a basal diet containing 300 mg/kg mixed MG. The results revealed that dietary MG significantly (P < 0.05) increased the body weight and average feed intake, but notably reduced the feed conversion and mortality of chickens in large-scale production during the starter phase. The villus height of the duodenum in the MG group at 1, 2 and 7 wk of age increased notably, and the villus height to crypt depth ratio at 1, 2, 5 and 10 wk of age was improved. Dietary MG decreased the serum insulin content of chickens at 5, 7 and 10 wk of age, and decreased the serum lipopolysaccharide at 3 and 7 wk of age. The triglyceride level of chickens at 3, 5 and 10 wk of age and the low-density lipoprotein cholesterol level of chickens at 7 and 10 wk of age in the MG group decreased notably, while the high-density lipoprotein cholesterol increased significantly. Moreover, MG supplementation selectively increased the relative abundance of genus Bacteroides (family Bacteroidaceae) and Lachnospiraceae_NK4A136_group, but decreased the content of genus Rikenellaceae_RC9_gut_group, Collinsella and family Barnesiellaceae in the cecum of chickens at 3, 7 and 10 wk of age. Conclusively, these findings showed that dietary MG notably enhanced chicken performance, health and feed nutrient utilization at early ages by regulating gut microbiota, intestinal development and serum biochemical indices.

Bacteria from the gut influence the host micronutrient status

Micronutrient deficiencies or "hidden hunger" remains a serious public health problem in most low- and middle-income countries, with severe consequences for child development. Traditional methods of treatment and prevention, such as supplementation and fortification, have not always proven to be effective and may have undesirable side-effects (i.e., digestive troubles with iron supplementation). Commensal bacteria in the gut may increase bioavailability of specific micronutrients (i.e., minerals), notably by removing anti-nutritional compounds, such as phytates and polyphenols, or by the synthesis of vitamins. Together with the gastrointestinal mucosa, gut microbiota is also the first line of protection against pathogens. It contributes to the reinforcement of the integrity of the intestinal epithelium and to a better absorption of micronutrients. However, its role in micronutrient malnutrition is still poorly understood. Moreover, the bacterial metabolism is also dependent of micronutrients acquired from the gut environment and resident bacteria may compete or collaborate to maintain micronutrient homeostasis. Gut microbiota composition can therefore be modulated by micronutrient availability. This review brings together current knowledge on this two-way relationship between micronutrients and gut microbiota bacteria, with a focus on iron, zinc, vitamin A and folate (vitamin B9), as these deficiencies are public health concerns in a global context.

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.

An investigation of the effect of folic acid and its delivery routes on broiler chickens' hatch and growth performance, blood biochemistry, anti-oxidant status, and intestinal morphology

This study investigated the effect of folic acid (FA) and its delivery routes (in-feed or in ovo) on broiler chicken's hatch and growth performance, blood biochemistry, anti-oxidant status, and intestinal morphology. A total of 1,860 Cobb 500 hatching eggs were incubated for 21 d. On day 12 of incubation, viable eggs were randomly allotted to four groups: the noninjected group, in ovo saline (injected with 0.1 mL/egg of saline solution), in ovo FA 1 (injected with 0.1 ml FA containing 0.1 mg/egg; FA1), and in ovo FA 2 (injected with 0.1 ml FA containing 0.15 mg/egg). All in ovo treatments were delivered via the amnion. At hatch, chicks were re-allotted to five new treatment groups: FA1, FA2, in-feed FA (FA 3; 5mg/kg in feed), in-feed bacitracin methylene disalicylate (BMD; 55 mg/kg in feed), and negative control (NC; corn-wheat-soybean diet) in 6 replicate pens (22 birds/pen) and raised in starter (days 0 to14), grower (days 15 to 24), and finisher (days 25 to 35) phases. Hatch parameters were assessed on day 0, and body weight and feed intake (FI) were determined weekly. On day 25, 1 bird/cage was euthanized, immune organs weighed, and intestinal tissues harvested. Blood samples were collected for biochemistry and anti-oxidant (Superoxide dismutase-SOD and Malondialdehyde-MDA) analysis. Data were analyzed in a randomized complete block design. While FA1 and FA2 decreased (P < 0.001) hatchability in a dose-dependent manner, FA2 caused a 2% increase (P < 0.05) in average chick weight compared to the noninjected group. Compared to the BMD treatment, FA3 decreased (P < 0.05) average FI across all feeding phases. At the end of the trial on day 35, FA2 had similar feed conversion ratio as the BMD treatment while recording less (P < 0.001) FI. FA1 and FA2 recorded a tendency (P < 0.1) to increase MDA levels and SOD activity by 50% and 19%, respectively, compared to the NC treatment. Compared to NC treatment, FA2 increased (P < 0.01) villus height, width, and villus height to crypt depth ratio in the duodenum, and villus width in the jejunum. Besides its negative effect on hatchability, FA2 may help improve embryonic development and anti-oxidant status in broiler chickens.