Navy bean supplemented high-fat diet improves intestinal health, epithelial barrier integrity and critical aspects of the obese inflammatory phenotype.

Obesity is associated with impaired intestinal epithelial barrier function and an altered microbiota community structure, which contribute to host systemic inflammation and metabolic dysfunction. Fiber-rich common beans (Phaseolus vulgaris) promote intestinal health (microbiota and host epithelial barrier integrity) in lean mice. The objective was to assess the intestinal health promoting effects of navy bean supplementation during high-fat (HF)diet-induced obesity. Male C57BL/6 mice were fed either a high-fat (HF) diet (60% of kcal from fat) or an isocaloric HF diet supplemented with 15.7% (by weight) cooked navy bean powder (HF+B) for 12 weeks. Compared to HF, the HF+B diet altered the fecal microbiota community structure (16S rRNA gene sequencing), most notably increasing abundance of Akkermansia muciniphila (+19-fold), whose abundance typically decreases in obese humans and rodents. Additionally, HF+B fecal abundance of carbohydrate fermenting, short chain fatty acid (SCFA) producing Prevotella (+332-fold) and S24-7 (+1.6-fold) and fecal SCFA levels were increased. HF+B improved intestinal health and epithelial barrier integrity versus HF, evidenced by reduced serum fluorescein isothiocyanate (FITC)-dextran concentration in an in vivo gut permeability test, and increased intestinal mRNA expression of tight junction components (ZO-1, occludin), anti-microbial defenses (Reg3γ, IgA, Defα5, Defß2) and mucins (Muc2). Additionally, HF+B improved the systemic obese phenotype via reduced serum HOMA-IR and leptin:adiponectin ratio, and locally via attenuation of epididymal adipose tissue crown-like structure formation, adipocyte size, and inflammatory transcription factor (NFκBp65 and STAT3) activation. Therefore, navy bean supplementation improved obese intestinal health (microbiota and epithelial barrier integrity) and attenuated the severity of the obese phenotype.

Chickpea supplementation prior to colitis onset reduces inflammation in dextran sodium sulfate-treated C57Bl/6 male mice.

The potential for a chickpea-supplemented diet (rich in fermentable nondigestible carbohydrates and phenolic compounds) to modify the colonic microenvironment and attenuate the severity of acute colonic inflammation was investigated. C57Bl/6 male mice were fed a control basal diet or basal diet supplemented with 20% cooked chickpea flour for 3 weeks prior to acute colitis onset induced by 7-day exposure to dextran sodium sulfate (DSS; 2% w/v in drinking water) and colon and serum levels of inflammatory mediators were assessed. Despite an equal degree of DSS-induced epithelial barrier histological damage and clinical symptoms between dietary groups, biomarkers of the ensuing inflammatory response were attenuated by chickpea pre-feeding, including reduced colon tissue activation of nuclear factor kappa B and inflammatory cytokine production (tumor necrosis factor alpha and interleukin (IL)-18). Additionally, colon protein expression of anti-inflammatory (IL-10) and epithelial repair (IL-22 and IL-27) cytokines were increased by chickpea pre-feeding. Furthermore, during acute colitis, chickpea pre-feeding increased markers of enhanced colonic function, including Relmß and IgA gene expression. Collectively, chickpea pre-feeding modulated the baseline function of the colonic microenvironment, whereby upon induction of acute colitis, the severity of the inflammatory response was attenuated.

Integrated Immunomodulatory Mechanisms through which Long-Chain n-3 Polyunsaturated Fatty Acids Attenuate Obese Adipose Tissue Dysfunction.

Obesity is a global health concern with rising prevalence that increases the risk of developing other chronic diseases. A causal link connecting overnutrition, the development of obesity and obesity-associated co-morbidities is visceral adipose tissue (AT) dysfunction, characterized by changes in the cellularity of various immune cell populations, altered production of inflammatory adipokines that sustain a chronic state of low-grade inflammation and, ultimately, dysregulated AT metabolic function. Therefore, dietary intervention strategies aimed to halt the progression of obese AT dysfunction through any of the aforementioned processes represent an important active area of research. In this connection, fish oil-derived dietary long-chain n-3 polyunsaturated fatty acids (PUFA) in the form of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been demonstrated to attenuate obese AT dysfunction through multiple mechanisms, ultimately affecting AT immune cellularity and function, adipokine production, and metabolic signaling pathways, all of which will be discussed herein.