The intestine or gut contains a community of bacteria responsible for maintaining an optimal environment affecting human health. Numerous studies have already linked disruption of the gut community to symptoms characteristic of autism and other health conditions. Now a new study by the Buck Institute for Research on Aging has confirmed that altering the community of gut bacteria promoted health and increases lifespan.
The research was published in the journal Cell and examined the impact of health and increased lifespan in Drosophila by altering the symbiotic, or commensal, relationship between bacteria and the absorptive cells lining the intestine.
The findings suggest that the bacterial load in intestines increases dramatically with age, resulting in an inflammatory condition driven by chronic activation of a stress response gene called FOXO. The stress gene suppresses the molecules that regulate immune response to the bacteria allowing bacterial numbers to expand, triggering an inflammatory response that includes the production of free radicals. Free radicals, in turn, cause over-proliferation of stem cells in the gut, resulting in epithelial dysplasia, a pre-cancerous state.
“Our study explores age-related changes in the gut that include increased oxidative stress, inflammation, impaired efficiency of the immune response, and the over-proliferation of stem cells,” said Heinrich Jasper, PhD, lead author of the study. “It puts these changes into a hierarchical, causal relationship and highlights the points where we can intervene to rescue the negative results of microbial imbalance.”
A prior study, published in Environmental Microbiology, demonstrated the role of breastfeeding in establishing a healthy gut in infants and found that bacteria can travel from the mother’s gut through her breast milk to the infant.
The Zurich research team found the same strains of Bifidobacterium breve and several types of Clostridium bacteria, which are important for colonic health, in breast milk, and maternal and/or neonatal faeces. Strains found in breast milk may be involved in establishing a critical nutritional balance in the baby’s gut and may be important to prevent intestinal disorders.
Linlin Guo, Jason Karpac, Susan L. Tran, Heinrich Jasper. PGRP-SC2 Promotes Gut Immune Homeostasis to Limit Commensal Dysbiosis and Extend Lifespan. Cell, 2014; 156 (1-2): 109 DOI: 10.1016/j.cell.2013.12.018
Wiley (2013, August 22). Breast is best: Good bacteria arrive from mum’s gut via breast milk. ScienceDaily