Mucin-mimetic action of capsaicin improves high fat diet-induced gut barrier dysfunction in mice colon

Abstract

The gut barrier – including tight junction proteins and mucus layers, is the first line of defense against physical, chemical, or pathogenic incursions. This barrier is compromised in various health disorders. Capsaicin, a dietary agonist of Transient receptor potential vanilloid 1 (TRPV1) channel, is reported to alleviate the complications of obesity. While its mode of action is well established to enhance energy expenditure, metabolism and prevent dysbiosis, the more local effects on the host gut – particularly the gut barrier and mucus system remain elusive.We employed a diet-induced obesity model to investigate the effect of capsaicin on the gut barrier and mucus production and to understand the involvement of mucus, bacteria, and TRPV1 in these phenomena. Mucin feeding reflected most of the effects produced by capsaicin, indicating that mucus modulation by capsaicin plays a crucial role in its anti-obesity effects. Capsaicin, bacteria and the host mucus system seem to act in a cyclic cascade involving TRPV1, which can be activated by capsaicin and various bacteria. These findings provide new insight into the role of TRPV1 in maintaining a healthy gut environment.HIGHLIGHTSExogenous mucin feeding produced anti-obesity effects similar to capsaicin in mice.Mucin and capsaicin improved TJP expression, intestinal permeability and gut microbial diversity.Capsaicin modulated bacterial diversity in vitro, independently of the host.Probiotic bacteria and butyrate activated TRPV1 in transfected HEK cells.Anti-obesity action of capsaicin is not exclusive to TRPV1 agonism.Capsaicin’s action as colonic mucus secretagogue – plays a crucial part in its anti-obesity benefits.

Oleuropein Prevents OVA‐Induced Food Allergy in Mice by Enhancing the Intestinal Epithelial Barrier and Remodeling the Intestinal Flora

“…The gut barrier represents the first line of defense against allergen invasion. [ 30 ] As important components of the intestinal epithelial barrier, TJ proteins are the physical barrier, while mucus and anti‐microbial peptides (such as regenerating gene (Reg) IIIγ) function as chemical barriers. [ 31 ] As shown in Figure 6 , the TJ protein expression in the Model group was inhibited, and the Reg IIIγ (68.52 ± 3.44 pg mL −1 vs 55.13 ± 1.22 pg mL −1 ) level was decreased, while the claudin‐1, occludin, and zonula occludens‐1 (ZO‐1) levels were reduced to 28.02, 32.28, and 23.32 pg mL −1 , respectively.…”