Antibiotics, immunity and obesity

Studies have shown that low doses of antibiotics administered to mice at an early age can lead to obesity in adulthood.

A short-term, low-dose dose of antibiotics administered shortly after birth in mice has long-lasting consequences for intestinal microbes, and rodents cause obesity as soon as they reach middle age. These findings, published today (August 14) in the journal Cytology, indicate that gut microbes are a key time window in early life and may affect the development of metabolic pathways.

For decades, low doses of antibiotics have been used to promote animal growth in agriculture, although the mechanism of drug fattening remains unclear. An article in a 2012 natural journal by Martin Blaser of the University of New York at Langone Medical Center and his colleagues showed that antibiotic treatment in early life of mice alters hormone levels in mice and participates in genes involved in carbohydrate and lipid metabolism. change.

Blaser told the journal Science that the latest study, his and his colleagues, aims to better understand how these therapeutic mechanisms mediate the effects of microbes on host metabolism. The researchers used two groups of low-dose penicillin-treated mice, one for imminent mice and the other for weaning mice. The third group is given antibiotics after the mice have been weaned. The low doses of penicillin used in these experiments did lead to an obesity and a proportional proportion of the dominant flora in the gut, but not enough to reduce the microbial population in the gut.

The level of lactic acid bacteria in the intestine of treated mice was significantly lower than that of untreated mice; the other two bacteria, Candidatus and Allobaculum, usually peaked in early life but were inhibited by small doses of penicillin.

Federico Rey, a microbiologist at the University of Madison, said, "We usually see that high doses of antibiotics reduce microbial diversity, but this is a typical "antibiotic bomb" and he is not involved in the work. "In this case, Inhibition of dominant bacteria may allow other species to thrive. ” Penicillin-treated post-weaning mice accelerated growth, bone mineral content changed, and fat and overall weight increased compared to untreated mice. However, the mother is treated before and during the breeding process, which has a greater impact on the offspring. Blaser said, “It’s enough to just give the mice four weeks of antibiotics,” he added. “Basically, the sooner, the stronger.” Antibiotic treatment plus a high-fat diet can exacerbate the effects of inducing obesity. Antibiotic-induced microbial changes also affect host intestinal cells; researchers have found reduced expression of gut immune response genes, such as those associated with Th17 and antimicrobial peptide production.

Laura Cox, a postdoctoral fellow at Basso Laboratory and co-author of the study, said "this seems to be a low dose of penicillin that reduces microbial signals and helps these immune responses occur."

To determine if these effects trigger microbial changes, Cox, Blaser and their colleagues transferred antibiotic-treated and untreated mouse intestinal microbes to sterile animals. The transferers mimicked their initial treatment: mice receiving the penicillin-treated flora gained weight, whereas the control animals did not. However, this effect was gradually reduced when the second generation of sterile mice received intestinal microbes from the first generation of treated mice. According to Cox, the transient effect may be due to the fact that these mice were processed later in life.

Brett Finlay, a microbiologist at the University of Lunda in Canada, asked, “We already know that using antibiotics in other animals leads to weight gain, so why are they not in mice?” He did not participate in the study. “The effect of transferring microbes to regain weight has basically proved that it is related to microbes,” he added.

Rey said the data is "objective and complete," "the impact is huge, especially when you put this on epidemiological data."

He added, and the results of this mouse-controlled study "provide varying degrees of evidence" between the link between antibiotics and long-term health.

From:
http://?articles.view/articleNo/40773/title/Antibiotics--Immunity--and-Obesity/
(Lianke Biological Translation)