Short-term trivalent arsenic and hexavalent chromium exposures induce gut dysbiosis and transcriptional alteration in adipose tissue of mice.

BACKGROUND: Inorganic arsenic [As(III)] and hexavalent chromium [Cr(VI)] can potentially affect metabolic functions. These heavy metal(s)/metalloids can also affect the gut microbial architecture which affects metabolic health. Here, we assessed the effects of short-term exposure of As(III) and Cr(VI) on key transcription factors in adipose tissues and on selected gut microbial abundances to understand the possible modulatory role of these toxicants on host metabolic health. METHODS AND RESULTS: qRT-PCR based relative bacterial abundance studies in cecal samples, gene expression analysis for gut wall integrity in ileum and colon and adipogenesis, lipolysis, and thermogenic genes in gonadal white and brown adipose tissue (gWAT and BAT), along with tissue oxidative stress parameters have been performed. As(III) and Cr(VI) exposure reduced beneficial Lactobacilli, Bifidobacteria, Akkermansia, Lachenospiraceae, Fecalibacterium, Eubacterium, and clostridium coccoid group while increasing lipopolysaccharides producing Enterobacteriaceae abundances. It also impaired structural features and expression of key tight junction and mucin production genes in ileum and colon (Cld-2, Cld-4, ZO-1, ZO-2, MUC-2 and - 4). In gWAT it inhibited adipogenesis (PPARγ, FASN, SREBP1a), lipolysis (HSL, ACOX-1), and thermogenesis (UCP-1, PGC1a, PRDM-16, PPARa) related genes expression, whereas in BAT, it enhanced adipogenesis and reduced thermogenesis. These exposures also reduces the endogenous antioxidants levels in these tissues and promote pro-inflammatory cytokines genes expression (TLRs, IL-6, MCP-1). The combinatorial exposure appears to have more deleterious effects. CONCLUSION: These effects of As(III) and Cr(VI) may not directly be linked to their known toxicological effects, instead, more intriguing crosstalk with gut microbial ecosystem hold the key.

Prevalence and associated factors of overweight/obesity among school going children in Chandigarh, India.

BACKGROUND: An increasing prevalence of childhood obesity is reported worldwide. Few data are available regarding childhood obesity in North India. The present study aimed to study the prevalence of overweight/obesity among adolescents aged 10-14, in schools of Chandigarh, and to examine associated factors. METHODS: Nine co-educational schools were chosen to include both government and private schools in Chandigarh. We randomly sampled students from different subsections/batches of classes fifth to ninth (aged 10-14), and those present on the day were measured and completed questionnaires. Obesity was classified according to the methods recommended by the Indian Association of Pediatrics (IAP) growth charts committee. RESULTS: A total of 1,030 participants were included, 502 students from government and 528 students from private schools. The overall prevalence of overweight and obesity evaluated by using age-specific body mass index (BMI) cut-offs was found to be 9.9% and 14.0%, respectively. The prevalence of overweight (adult equivalent of 23) was 10.3% in boys and 9.4% in girls and that of obesity (adult equivalent of 27) was found to be 13.3% and 14.7%, respectively, in boys and girls. In univariate analyses, statistically significant associations were found between the risk of obesity and gender, socio-economic status (SES) and reported physical activity. CONCLUSION: We found significant levels of overweight and obesity among children aged 10-14 and found associations with SES, gender and reported physical activity as has been previously reported elsewhere.

Co-supplementation of isomalto-oligosaccharides potentiates metabolic health benefits of polyphenol-rich cranberry extract in high fat diet-fed mice via enhanced gut butyrate production.

PURPOSE: Cranberries are a rich source of polyphenolic antioxidants. Purified sugars or artificial sweeteners are being added to cranberry-based food products to mask tartness. Refined sugar and artificial sweeteners intake modulate gut microbiota and result in metabolic complications. We evaluated effects of isomalto-oligosaccharides (IMOs; sweet tasting non-digestible oligosaccharides) with cranberry extract (CRX) on high fat diet (HFD)-induced metabolic alterations in mice. METHODS: Male Swiss albino mice were fed normal chow or HFD (58% fat kcal), and were administered either CRX (200 mg/kg) alone or in combination with IMOs (1 g/kg). Cecal short-chain fatty acids, abundances of selected (1) butyrate producing, (2) metabolically beneficial, and (3) selective lipopolysaccharides producing gram negative gut bacteria were studied. Further, gut-related histological, biochemical, genomic changes along with circulating pro-/anti-inflammatory markers and systemic obesity-associated metabolic changes were studied. RESULTS: Co-supplementation of CRX and IMOs significantly improved cecal SCFAs, especially butyrate levels, selected butyrate-producing bacteria (clostridial cluster XIVa bacteria) and butyrate kinase expression in HFD-fed mice. The combination also significantly improved gut beneficial bacterial abundance, gut histology and related changes (colon mucin production, gut permeability) as compared to individual agents. It also prevented HFD-induced systemic and tissue inflammation, glucose intolerance and systemic obesity-associated metabolic changes in adipose tissue and liver. The combination of CRX and IMOs appeared more effective in the prevention of HFD-induced gut derangements. CONCLUSION: Combination of CRX and IMOs could be advantageous for normalization of metabolic alterations seen in diet-induced obesity via beneficial modulation of gastrointestinal health.

Isomalto-oligosaccharides, a prebiotic, functionally augment green tea effects against high fat diet-induced metabolic alterations via preventing gut dysbacteriosis in mice.

High fat diet (HFD)-induced alterations in gut microbiota and resultant 'leaky gut' phenomenon promotes metabolic endotoxemia, ectopic fat deposition, and low-grade systemic inflammation. Here we evaluated the effects of a combination of green tea extract (GTE) with isomalto-oligosaccharide (IMOs) on HFD-induced alterations in mice. Male Swiss albino mice were fed with HFD (58% fat kcal) for 12 weeks. Systemic adiposity, gut derangement parameters and V3-V4 region based 16S rRNA metagenomic sequencing, ectopic fat deposition, liver metabolome analysis, systemic and tissue inflammation, and energy homeostasis markers along with gene expression analysis in multiple tissues were done in mice supplemented with GTE, IMOs or their combination. The combination of GTE and IMOs effectively prevented HFD-induced adiposity and lipid accumulation in liver and muscle while normalizing fasting blood glucose, insulin, glucagon, and leptin levels. Co-administration of GTE with IMOs effectively modulated liver metabolome associated with lipid metabolism. It also prevented leaky gut phenotype and HFD-induced increase in circulating lipopolysaccharides and pro-inflammatory cytokines (e.g. resistin, TNF-α, and IL-1ß) and reduction in anti-inflammatory cytokines (e.g. adiponectin and IL-6). Gene expression analysis across multiple tissues further supported these functional outcomes. Most importantly, this combination improved beneficial gut microbiota (Lactobacillus sp., Bifidobacteria, Akkermansia muciniphila, Roseburia spp.) abundances, restored Firmicutes/Bacteriodetes and improved Prevotella/Bacteroides proportions. In particular, a combination of these two agents has shown improved beneficial effects on multiple parameters studied. Data presented herein suggests that strategically chosen food components might be highly effective in the prevention of HFD-induced alterations and may further be developed as functional foods.

Finger millet arabinoxylan protects mice from high-fat diet induced lipid derangements, inflammation, endotoxemia and gut bacterial dysbiosis.

Arabinoxylan (AX), a non-starch polysaccharide extracted from cereals such as wheat, rice and millets, is known to impart various health promoting effects. Our earlier study suggested that finger millet (FM) could ameliorate high fat diet (HFD)-induced metabolic derangements. The present study is aimed to evaluate the effect of FM-AX supplementation, a key bioactive from finger millet, on HFD-induced metabolic and gut bacterial derangements. Male Swiss albino mice were fed with normal chow diet (NPD) or HFD (60%kcal from fat) for 10 weeks. FM-AX was orally supplemented at doses of 0.5 and 1.0g/kg bodyweight on every alternate day for 10 weeks. Glucose tolerance, serum hormones, hepatic lipid accumulation and inflammation, white adipose tissue marker gene expression, adipocyte size and inflammation; metagenomic alterations in cecal bacteria; cecal short chain fatty acids and colonic tight junction gene expressions were studied. FM-AX supplementation prevented HFD-induced weight gain, alerted glucose tolerance and serum lipid profile, hepatic lipid accumulation and inflammation. Hepatic and white adipose tissue gene expressions were beneficially modulated. Further, AX supplementation prevented metagenomic alterations in cecum; improved ileal and colonic health and overall prevented metabolic endotoxemia. Present work suggests that AX from finger millet can be developed as a nutraceutical for the management of HFD- induced obesity.