This week on BBS: we find that early antibiotic use increases obesity in boys, the gut microbiota influences cancer treatments and Staphylococcus epidermidis fights acne.
Antibiotics and High BMI
Research is showing that the intestinal microflora has an impact on the development of obesity. This could suggest that an individual’s weight could be influenced by early use of antibiotics, which are known to permanently disturb the relative composition of the microbiota. To find out more, researchers at the University of Auckland in New Zealand investigated the early use of antibiotics in 946 children from various centers. They found that the BMI was significantly increased in young boys that had an early history of antibiotic use. This result was not found in girls. This further supports that the intestinal microbiota influences obesity risk. See the post about probiotics and weight loss for more information.
Microbiota and Cancer Treatments
Intestinal bacteria influence the immune system. New methods of cancer treatment, tumor immunotherapy, rely on immune cells to attack and eliminate cancer, which would mean that the gut microbiota could modulate these new approaches. Researchers from the National Cancer Institute looked at this question by examining the effectiveness of tumor immunotherapy in mice either treated with antibiotics or bred in germ-free facilities. They found that mice with limited or no gut bacteria had immune cells, which responded poorly during the treatments. The best responses were with mice with a healthy microflora.
Acne-fighting Staphylococcus epidermidis
The intestines aren’t the only place with bacteria. The skin has its own microbiota, which is important to maintaining the health of our largest organ. One very common skin complaint is acne, however, it wasn’t known how the microflora might keep acne-causing bacteria, like Propionibacterium acnes, in check. In a study by the University of California at San Diego, it was found that Staphylococcus epidermidis is really important for keeping the growth of P. acnes under control. The main weapon of S. epidermidis was the fermentation of skin-derived glycerol to succinic acid, which inhibited P. acnes growth.
- Murphy R, Stewart AW, Braithwaite I, Beasley R, Hancox RJ, Mitchell EA. Antibiotic treatment during infancy and increased body mass index in boys: an international cross-sectional study. Int J Obes (Lond) 2013. [Epub ahead of print]
- Iida N, Dzutsev A, Stewart CA, Smith L, Bouladoux N, Weingarten RA et al. Commensal bacteria control cancer response to therapy by modulating the tumor microenvironment. Science 2013; 342(6161): 967-970.
- Wang Y, Kuo S, Shu M, Yu J, Huang S, Dai A et al. Staphylococcus epidermidis in the human skin microbiome mediates fermentation to inhibit the growth of Propionibacterium acnes: implications of probiotics in acne vulgaris. Appl Microbiol Biotechnol 2013. [Epub ahead of print]