Effects of high fructose corn syrup on intestinal microbiota structure and obesity in mice

Safety assessment of high fructose corn syrup and fructose used as sweeteners in foods

High Fructose Corn Syrup (HFCS) and Fructose (FR) are widely used sweeteners in many foods and beverages. This study aimed at investigating the cytotoxic effects of HFCS (5%-30%) and FR (62.5-2000 μg/mL) using MTT assay in Human Hepatocellular Carcinoma (HepG2) cells, and genotoxic effects of using Chromosome Aberrations (CAs), Sister Chromatid Exchanges (SCEs), Micronuclei (MN) and comet assays in human lymphocytes. HFCS significantly reduced the cell viability in HepG2 cells at between 7.5% and 30% for 24 and 48 h. 30% HFCS caused a very significant toxic effect. FR had a cytotoxic effect in HepG2 cells at all treatments. However, as fructose concentration decreased, the cell viability decreased. HFCS (10%-20%) and FR (250-2000 μg/mL) decreased the mitotic index at higher concentrations. IC50 value was found to be a 15% for 48 h. IC50 value of FR was detected as 62.5 μg/mL for 24 h and 48 h. HFCS significantly increased CAs frequency at 15% and 20%. FR significantly increased the frequency of CAs at 250, 1000, and 2000 μg/mL for 48 h. Both sweeteners increased the frequency of SCEs at all concentrations. HFCS (15% and 20%) and FR (250, 1000, and 2000 μg/mL) induced MN frequency at higher concentrations. HFCS caused DNA damage in comet assay at 10% -30%. FR increased tail intensity and moment at 125-2000 μg/mL and tail length at 62.5, 250 and 500 μg/mL. Therefore, HFCS and FR are clearly seen to be cytotoxic and genotoxic, especially at higher concentrations.

Effects of Excessive High-fructose Corn Syrup Drink Intake in Middle-aged Mice

BACKGROUND/AIM

The global prevalence of type 2 diabetes (T2D) continues to increase, necessitating the need for understanding the causes of its development. The widespread use of high-fructose corn syrup (HFCS) in drinks and diets is suspected to play a role in metabolic disorders. Although many studies have reported on the effects of excessive HFCS and excessive energy intakes in middle-aged individuals, few have focused on energy restriction. This study aimed to investigate the effects of excessive HFCS drink intake under energy restriction on developing T2D in early middle-aged mice.

MATERIALS AND METHODS

Early middle-aged mice were divided in HFCS and control groups; they were provided either 10% HFCS water or deionized water ad libitum for 12 weeks, respectively. Total energy intake was controlled using a standard rodent diet. Oral glucose tolerance test (OGTT), insulin tolerance test (ITT), tissue weight measurements, serum parameter analyses, and mRNA expression assessments were performed.

RESULTS

No increase in body and adipose tissue weight was observed with excessive HFCS intake under energy restriction. Moreover, serum lipid parameters did not differ from those of controls. However, in the OGTT and ITT, the HFCS group showed higher blood glucose levels than the control group. Moreover, the pancreatic weight and insulin II mRNA expression were reduced.

CONCLUSION

The excessive HFCS drink intake under energy restriction did not induce obesity; however, it induced impaired glucose tolerance, indicating its negative effects on the pancreas in early middle-aged mice. When translated in human physiology, our results show that even if one does not become obese, excessive HFCS may affect the overall metabolic mechanism; these effects may vary depending on age.

Assessing the impact of three feeding stages on rumen bacterial community and physiological characteristics of Japanese Black cattle

In Japan, Japanese Black cattle, known for their exceptional meat quality owing to their abundant intramuscular fat, undergo a unique three-stage feeding system with varying concentrate ratios. There is limited research on physiological and rumen microbial changes in Japanese Black cattle during these stages. Therefore, this study aimed to examine Japanese Black steers in these three stages: early (T1, 12-14 months), middle (T2, 15-22 months), and late (T3, 23-30 months). The rumen bacteria of 21 cattle per phase was analyzed using 16S rRNA gene sequencing. Rumen bacterial diversity was significantly higher in T1, with a distinct distribution, than in T2 and T3. Specific phyla and genera were exclusive to each stage, reflecting the shifts in feed composition. Certain genera dominated each stage: T1 had Flexilinea, Streptococcus, Butyrivibrio, Selenomonas, and Kandleria; T2 had Bifidobacterium, Shuttleworthia, and Sharpea; and T3 had Acetitomaculum, Mycoplasma, Atopobium, and Howardella. Correlation analysis revealed significant associations between certain microbial populations and physiological parameters. These findings indicate that changes in energy content and feed composition are associated with physiological and ruminal alterations. This study may guide strategies to improve rumen health and productivity in Japanese Black cattle by modifying diets to specific fattening stages.

Impact of Sustained Fructose Consumption on Gastrointestinal Function and Health in Wistar Rats: Glycoxidative Stress, Impaired Protein Digestion, and Shifted Fecal Microbiota

The gastrointestinal tract (GIT) is the target of assorted pathological conditions, and dietary components are known to affect its functionality and health. In previous in vitro studies, we observed that reducing sugars induced protein glycoxidation and impaired protein digestibility. To gain further insights into the pathophysiological effects of dietary sugars, Wistar rats were provided with a 30% (w/v) fructose water solution for 10 weeks. Upon slaughter, in vivo protein digestibility was assessed, and the entire GIT (digests and tissues) was analyzed for markers of oxidative stress and untargeted metabolomics. Additionally, the impact of sustained fructose intake on colonic microbiota was also evaluated. High fructose intake for 10 weeks decreased protein digestibility and promoted changes in the physiological digestion of proteins, enhancing intestinal digestion rather than stomach digestion. Moreover, at colonic stages, the oxidative stress was harmfully increased, and both the microbiota and the intraluminal colonic metabolome were modified.

Gut Microbiome and Lipidome Signatures in Irritable Bowel Syndrome Patients from a Low-Income, Food-Desert Area: A Pilot Study

Irritable bowel syndrome (IBS) is a common gastroenterological disorder with triggers such as fructose. We showed that our IBS patients suffering from socioeconomic challenges have a significantly high consumption of high-fructose corn syrup (HFCS). Here, we characterize gut microbial dysbiosis and fatty acid changes, with respect to IBS, HFCS consumption, and socioeconomic factors. Fecal samples from IBS patients and healthy controls were subjected to microbiome and lipidome analyses. We assessed phylogenetic diversity and community composition of the microbiomes, and used linear discriminant analysis effect size (LEfSe), analysis of compositions of microbiomes (ANCOM) on highly co-occurring subcommunities (modules), least absolute shrinkage and selection operator (LASSO) on phylogenetic isometric log-ratio transformed (PhILR) taxon abundances to identify differentially abundant taxa. Based on a Procrustes randomization test, the microbiome and lipidome datasets correlated significantly (p = 0.002). Alpha diversity correlated with economic factors (p < 0.001). Multiple subsets of the phylogenetic tree were associated with HFCS consumption (p < 0.001). In IBS patients, relative abundances of potentially beneficial bacteria such as Monoglobaceae, Lachnospiraceae, and Ruminococcaceae were lower (p = 0.007), and Eisenbergiella, associated with inflammatory disorders, was higher. In IBS patients, certain saturated fatty acids were higher and unsaturated fatty acids were lower (p < 0.05). Our study aims first to underscore the influence of HFCS consumption and socioeconomic factors on IBS pathophysiology, and provides new insights that inform patient care.

Effects of Solid Fermentation on Polygonatum cyrtonema Polysaccharides: Isolation, Characterization and Bioactivities

Polygonati Rhizoma is a widely used traditional Chinese medicine (TCM) with complex pre-processing steps. Fermentation is a common method for processing TCM to reduce herb toxicity and enhance their properties and/or produce new effects. Here, in this study, using Bacillus subtilis and Saccharomyces cerevisiae, we aimed to evaluate the potential application of solid fermentation in isolating different functional polysaccharides from Polygonatum cyrtonema Hua. With hot water extraction, ethanol precipitation, DEAE anion exchange chromatography and gel filtration, multiple neutral and acidic polysaccharides were obtained, showing different yields, content, compositions and functional groups after fermentation. Combining in vitro experiments and in vivo aging and immunosuppressed mouse models, we further compared the antioxidant and immunomodulating bioactivities of these polysaccharides and found a prominent role of a natural polysaccharide (BNP) from fermented P. cyrtonema via Bacillus subtilis in regulating intestinal antioxidant defense and immune function, which may be a consequence of the ability of BNP to modulate the homeostasis of gut microbiota. Thus, this work provides evidence for the further development and utilization of P. cyrtonema with fermentation, and reveals the potential values of BNP in the treatment of intestinal disorders.

Soda intake influences phenotype, antioxidants and inflammatory status in high protein-fed wistar rats

An increasing population of people, especially young adults who exercise, consume high protein diets along with carbonated drinks. While there are numerous studies on the effect of high protein diets, there is a need to understand how protein diets in combination with carbonated drinks impact physiology. In order to assess these effects on wistar rats' phenotype, antioxidants and inflammatory profiles, 64 wistar rats were divided into dietary groups of 8 male and 8 female animals each. The animals were fed standard diet as control (chow), chow and carbonated soda, a high protein diet (48.1% energy from protein) and a high protein diet with carbonated soda according to their groups. Body measurements, blood glucose levels, serum insulin levels, lipid peroxidation, antioxidant activity, adipokines and inflammatory markers concentrations were all determined. At the end of the study, body measurements, inflammatory markers and adipokine concentration were increased in animals fed the high protein diet and high protein-soda diet. There was a decrease in antioxidant and lipid peroxidation levels in protein fed male and female animals but those fed protein in combination with soda had increased lipid peroxidation levels. In conclusion, high protein diet in combination with carbonated soda impacts physiology differently from a high protein diet alone, and may stimulate weight gain, oxidative stress and HPD-related inflammation in Wistar rats.

The number of metabolic syndrome risk factors predicts alterations in gut microbiota in Chinese children from the Huantai study

BACKGROUND

Evidence on the effect of gut microbiota on the number of metabolic syndrome (MetS) risk factors among children is scarce. We aimed to examine the alterations of gut microbiota with different numbers of MetS risk factors among children.

METHODS

Data were collected from a nested case-control study at the baseline of the Huantai Childhood Cardiovascular Health Cohort Study in Zibo, China. We compared the differences in gut microbiota based on 16S rRNA gene sequencing among 72 children with different numbers of MetS risk factors matched by age and sex (i.e., none, one, and two-or-more MetS risk factors; 24 children for each group).

RESULTS

The community richness (i.e., the total number of species in the community) and diversity (i.e., the richness and evenness of species in the community) of gut microbiota decreased with an increased number of MetS risk factors in children (P for trend < 0.05). Among genera with a relative abundance greater than 0.01%, the relative abundance of Lachnoclostridium (P_FDR = 0.009) increased in the MetS risk groups, whereas Alistipes (P_FDR < 0.001) and Lachnospiraceae_NK4A136_group (P_FDR = 0.043) decreased in the MetS risk groups compared to the non-risk group. The genus Christensenellaceae_R-7_group excelled at distinguishing one and two-or-more risk groups from the non-risk group (area under the ROC curve [AUC]: 0.84 - 0.92), while the genera Family_XIII_AD3011_group (AUC: 0.73 - 0.91) and Lachnoclostridium (AUC: 0.77 - 0.80) performed moderate abilities in identifying none, one, and two-or-more MetS risk factors in children.

CONCLUSIONS

Based on the nested case-control study and the 16S rRNA gene sequencing technology, we found that dysbiosis of gut microbiota, particularly for the genera Christensenellaceae_R-7_group, Family_XIII_AD3011_group, and Lachnoclostridium may contribute to the early detection and the accumulation of MetS risk factors in childhood.

Association between Family and School Pressures, Consumption of Ultra-Processed Beverages, and Obesity in Preadolescents: A School-Based Epidemiological Study

The aim of the present work was two-fold. Firstly, to evaluate the association between the consumption of ultra-processed beverages (UPB) on preadolescents’ likelihood of being obese. Secondly, to investigate the potential impact of family and school environmental stressors on this unhealthy lifestyle habit. A cross-sectional study was conducted among 1718 Greek preadolescents and their parents, during the school years 2014 to 2016. Parental and child characteristics were collected anonymously, through self-administered and validated questionnaires. Among others, UPB consumption (soft and flavored drinks) was recorded, classifying children as low, moderate, or high consumers, while anthropometric characteristics [height, body weight, Body Mass Index (BMI)] were also recorded. Almost seven out of ten preadolescents were classified as at least moderate UPB consumers, while approximately three out of ten were classified as high UPB consumers. Higher UPB consumption was associated with significantly higher levels of BMI, while preadolescents living in a more stressful family and school environment were found to consume significantly higher amounts of UPB. Stakeholders should implement programs that raise awareness among parents and teachers about the sources of stress in preadolescence as a potential “triggering factor” of unhealthy dietary preferences.

Long-Term Protein Restriction Modulates Lipid Metabolism in White Adipose Tissues and Alters Colonic Microbiota of Shaziling Pigs

Obesity is a matter of concern to the public. Abundant evidence has been accumulated that nutritional intervention is a promising strategy to address this health issue. The objective of this study is to investigate alterations in the lipid metabolism in white adipose tissues and the gut microbiota of Shaziling pigs challenged by long-term protein restriction. Results showed that compared with the control group, reducing the protein level by 20% (−20%) increased the mRNA abundance of FABP4 in white adipose tissues (p < 0.05). This occurred in conjunction with increases in PPARγ protein expression. Conversely, the protein expression of C/EBPα was reduced in the −20% group (p < 0.05). Moreover, the −20% group had increased/decreased phosphorylation of AMPKα/mTOR, respectively (p < 0.05). As for the colonic gut microbiota, a 20% reduction in the protein level led to increased Lachnospiraceae XPB1014 group abundance at the genus level (p < 0.01). Collectively, these results indicated that a 20% protein reduction could modulate lipid metabolism and alter the colonic microbiota of Shaziling pigs, an approach which might be translated into a treatment for obesity.

Seasonal variations in gut microbiota of semiprovisioned rhesus macaques (Macaca mulatta) living in a limestone forest of Guangxi, China

Assessment of gut microbiota, used to explore ecological adaptation strategies and evolutionary potential of species, provides a new viewpoint to the conservation and management of endangered animals. In this research, the gut microbiota of a group of semiprovisioned rhesus macaques (Macaca mulatta) living in a limestone forest exhibiting seasonal changes in plant items were studied to investigate the adaptation strategies of these macaques to this specific habitat. The findings revealed significant seasonal changes in the diversity and composition of the rhesus macaques’ gut microbiota, which were higher in the rainy season than in the dry season. In the rainy season, Bacteroidetes (31.83 ± 16.14% vs. 19.91 ± 18.20%) were significantly increased and Prevotella (23.70 ± 15.33% vs. 15.40 ± 16.10%), UCG-002 (4.48 ± 3.16% vs. 2.18 ± 2.01%), and UCG-005 (4.22 ± 2.90% vs. 2.03 ± 1.82%) were more enriched at the genus level. In the dry season, Firmicutes significantly increased (71.84 ± 19.28% vs. 60.91 ± 16.77%), and Clostridium_sensu_stricto_1 (8.45 ± 9.72% vs. 4.76 ± 6.64%), Enterococcus (10.17 ± 13.47% vs. 0.69 ± 2.36%), and Sarcina (4.72 ± 7.66% vs. 2.45 ± 4.71%) were more enriched at the genus level. These differences in gut microbiota may be due to seasonal variations in plant items in these habitats alongside changes in the provisioned foods from tourists. Additionally, deterministic processes predominate the assembly of the macaque’s gut microbiota community. This indicates that the animal’s high reliance on natural plants and provisioned foods increased the impact of deterministic processes. This study concludes that a balance between provisioned foods and natural plants might be vital in shaping the gut microbiota in the macaques. Furthermore, the dynamic adjustment in gut microbiota might be a physiological mechanism for the macaques in response to the seasonal variations in the ecological factors and food provision.

The Effect of Short-Term Consumption of Lactic Acid Bacteria on the Gut Microbiota in Obese People

Obesity is a problem of modern health care that causes the occurrence of many concomitant diseases: arterial hypertension, diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular diseases. New strategies for the treatment and prevention of obesity are being developed that are based on using probiotics for modulation of the gut microbiota. Our study aimed to evaluate the bacterial composition of the gut of obese patients before and after two weeks of lactic acid bacteria (Lactobacillus acidophilus, Lactiplantibacillus plantarum, Limosilactobacillus fermentum, and Lactobacillus delbrueckii) intake. The results obtained showed an increase in the number of members of the phylum Actinobacteriota in the group taking nutritional supplements, while the number of phylum Bacteroidota decreased in comparison with the control group. There has also been an increase in potentially beneficial groups: Bifidobacterium, Blautia, Eubacterium, Anaerostipes, Lactococcus, Lachnospiraceae ND3007, Streptococcus, Escherichia-Shigella, and Lachnoclostridium. Along with this, a decrease in the genera was demonstrated: Faecalibacterium, Pseudobutyrivibrio, Subdoligranulum, Faecalibacterium, Clostridium sensu stricto 1 and 2, Catenibacterium, Megasphaera, Phascolarctobacterium, and the Oscillospiraceae NK4A214 group, which contribute to the development of various metabolic disorders. Modulation of the gut microbiota by lactic acid bacteria may be one of the ways to treat obesity.