Microbial reprogramming inhibits Western diet-associated obesity.

Area of Science:

• Immunology
• Microbiology
• Nutrition Science

Background:

• Epidemiological studies link 'fast food' to obesity and yogurt to weight management.
• The immune system plays a critical role in obesity development.
• Western diets induce pro-inflammatory immune responses and alter gut microbiota.

Purpose of the Study:

• To investigate the effects of a Western diet on immune profiles and obesity in humans and mice.
• To determine if probiotic yogurt or specific bacteria can prevent diet-induced obesity.
• To elucidate the mechanisms by which probiotics exert anti-obesity effects.

Main Methods:

• Human subjects and mouse models were fed a Western diet.
• Immune cell profiles (Th17, Treg), gut microbiota, and abdominal fat were analyzed.
• Mice were treated with probiotic yogurt or Lactobacillus reuteri ATCC 6475, and CD4(+) T cells were transferred.

Main Results:

• Western diet consumption led to Th17-biased immunity, altered microbiota, and increased abdominal fat.
• Probiotic yogurt and L. reuteri alone prevented weight gain and abdominal fat accumulation.
• L. reuteri therapy induced immune tolerance via regulatory T cells (Treg) and IL-10, independent of diet or caloric intake.
• Beneficial effects were transferable via CD4(+) T cells.

Conclusions:

• Oral L. reuteri therapy can prevent obesity and associated immune dysregulation.
• Microbial interventions targeting immune tolerance offer a novel approach for weight management.
• These findings suggest population-based strategies for public health in industrialized nations.