Dietary Capsaicin Improves Glucose Homeostasis and Alters the Gut Microbiota in Obese Diabetic ob/ob Mice

Abstract

Background: The effects of capsaicin on obesity and glucose homeostasis are still controversial and the mechanisms underlying these effects remain largely unknown. This study aimed to investigate the potential relationship between the regulation of obesity and glucose homeostasis by dietary capsaicin and the alterations of gut microbiota in obese diabetic ob/ob mice.Methods: The ob/ob mice were subjected to a normal, low-capsaicin (0.01%), or high-capsaicin (0.02%) diet for 6 weeks, respectively. Obesity phenotypes, glucose homeostasis, the gut microbiota structure and composition, short-chain fatty acids, gastrointestinal hormones, and pro-inflammatory cytokines were measured.Results: Both the low- and high-capsaicin diets failed to prevent the increase in body weight, adiposity index, and Lee's obesity index. However, dietary capsaicin at both the low and high doses significantly inhibited the increase of fasting blood glucose and insulin levels. These inhibitory effects were comparable between the two groups. Similarly, dietary capsaicin resulted in remarkable improvement in glucose and insulin tolerance. In addition, neither the low- nor high-capsaicin diet could alter the α-diversity and β-diversity of the gut microbiota. Taxonomy-based analysis showed that both the low- and high-capsaicin diets, acting in similar ways, significantly increased the Firmicutes/Bacteroidetes ratio at the phylum level as well as increased the Roseburia abundance and decreased the Bacteroides and Parabacteroides abundances at the genus level. Spearman's correlation analysis revealed that the Roseburia abundance was negatively while the Bacteroides and Parabacteroides abundances were positively correlated to the fasting blood glucose level and area under the curve by the oral glucose tolerance test. Finally, the low- and high-capsaicin diets significantly increased the fecal butyrate and plasma total GLP-1 levels, but decreased plasma total ghrelin, TNF-α, IL-1β, and IL-6 levels as compared with the normal diet.Conclusions: The beneficial effects of dietary capsaicin on glucose homeostasis are likely associated with the alterations of specific bacteria at the genus level. These alterations in bacteria induced by dietary capsaicin contribute to improved glucose homeostasis through increasing short-chain fatty acids, regulating gastrointestinal hormones and inhibiting pro-inflammatory cytokines. However, our results should be interpreted cautiously due to the lower caloric intake at the initial stage after capsaicin diet administration.

Physiological and Metabolic Effects of Yellow Mangosteen (Garcinia dulcis) Rind in Rats with Diet-Induced Metabolic Syndrome

“…Previous study showed that Lachnospiraceae was positively associated with diabetes [50]. Additionally, the abundance of Bacteroides and Parabacteroides was positively correlated while Roseburia was negatively correlated with fasting blood glucose and area under the curve in obese diabetic ob/ob mice fed with capsaicin [51].…”

Potential Phytopharmacy and Food Applications ofCapsicumspp.: A Comprehensive Review

“…In the obese diabetic model ob/ob mice, capsaicin (0.01-0.02% in the diet for 6 weeks) significantly suppressed the enhancement in fasting blood glucose, as well as also increased the insulin levels. Moreover, capsaicin significantly increased the fecal butyrate and plasma total GLP-1 levels, but decreased plasma total ghrelin, TNF-α, IL-1β, and IL-6 levels [192]. Capsaicin also reduced body weight via activating transient receptor potential vanilloid 1 (TRPV1) cation channel, improving glucose tolerance, up-regulating the expression of Mucin 2 gene Muc2 and antimicrobial protein gene Reg3g in the intestine of C57BL/6 mice [193].…”

Considering gut microbiota in treatment of type 2 diabetes mellitus

“…62,65,66 Increased fecal butyrate concentration and Roseburia abundance and decreased Bacteroides and Parabacteroides abundances have been reported after intervention by capsaicin in obese diabetic ob/ob mice. 65 Alliin from garlic caused a decrease in Lachnospiraceae abundance and an increase in Ruminococcaceae abundance, which enhanced glucose homeostasis and insulin sensitivity, but has no effect on adiposity. 67 Berberine decreased the relative abundance of branched-chain amino acids-producing bacteria, including Streptococcus and Prevotella whereas it increased the relative abundance of SCFAproducing bacteria, including Blautia and Allobaculum.…”

“…Additionally, a range of herbal-derived products including berberine, resveratrol, alliin, capsaicin, betacyanins, and cranberry proanthocyanidins have bioactions and antidiabetic effects potentially mediated by modulation of gut microbiota. [60][61][62][63][64][65][66][67] Galactomannan, pectin, capsaicin, and red pitaya betacyanins altered the proportion of Firmicutes to Bacteroidetes. 62,65,66 Increased fecal butyrate concentration and Roseburia abundance and decreased Bacteroides and Parabacteroides abundances have been reported after intervention by capsaicin in obese diabetic ob/ob mice.…”

“…[60][61][62][63][64][65][66][67] Galactomannan, pectin, capsaicin, and red pitaya betacyanins altered the proportion of Firmicutes to Bacteroidetes. 62,65,66 Increased fecal butyrate concentration and Roseburia abundance and decreased Bacteroides and Parabacteroides abundances have been reported after intervention by capsaicin in obese diabetic ob/ob mice. 65 Alliin from garlic caused a decrease in Lachnospiraceae abundance and an increase in Ruminococcaceae abundance, which enhanced glucose homeostasis and insulin sensitivity, but has no effect on adiposity.…”