Study shows calorie-restricted diet has a positive effect on immune system

A new study indicated that a calorie-restricted diet may alter the gut microbiome, improve metabolic health, and delay deterioration of the immune system due to age.

The study, published in the journal Microbiome, was conducted by researchers at the German Center for Diabetes Research (DZD), and led by Julia Sbierski-Kind, PhD. The study aimed to understand the relationship between a low-calorie diet, the gut microbiome, and the immune system. To do so, scientists observed how a low-calorie diet of 800 kcal/day for eight weeks impacted the gut microbiome of an obese woman. Then, scientists transplanted the gut microbiota from before the diet, and after the diet into germ-free mice.

"In this way, we were able to determine the sole effects of the diet-shaped gut microbiome on metabolism and the immune system," said Reiner Jumpertz von Schwartzenberg, MD, last author of the study and a scientist at the Institute of Diabetes Research and Metabolic Diseases of Helmholtz Munich at the University of Tübingen.

The researchers found that the diet-altered microbiota showed improved glucose metabolism, decreased fat deposition, and a reduced level of specific memory T and B cells, which could indicate a delay in immune system deterioration due to age, according to researchers.

"These findings suggest that the positive effects of a low-calorie diet on metabolism and the immune system are mediated via the gut microbiome," Sbierski-Kind said.

This study only involved one participant, and according to the study’s authors, more research on a low-calorie diet’s effect of the immune system is needed before any formal conclusions are reached. The researchers suggested that future findings based on this study may help develop new interventions to treat both metabolic and immune disease.