Gut bacteria restore quality in aging eggs
Egg quality declines faster than most other parts of the body. Now it turns out gut bacteria may slow that decline, through a molecule they produce.
Women trying to conceive later in life often face reduced egg quality. Eggs fertilize less successfully and carry a higher risk of chromosomal errors. This is one of the most tangible forms of reproductive aging. But what drives that decline, and can it be reversed?
New research discussed by the researchers shows that glutamic acid, an amino acid produced by gut bacteria, can improve the quality of aged oocytes. The gut microbiome, the community of bacteria living in the intestines, changes with age. Older guts produce less of certain useful compounds, including glutamic acid.
An amino acid as a bridge
Glutamic acid is one of the most common amino acids in the body. It plays a role in cellular energy production and in protecting against oxidative stress, a process in which harmful molecules (free radicals) damage cells. In aging oocytes, energy production by the mitochondria, the cell’s energy-generating structures, is substantially reduced.
The researchers found that supplementing with glutamic acid partially restored mitochondrial function in aged oocytes. The eggs divided more successfully, showed fewer chromosomal errors, and produced fewer markers of oxidative damage. Effects were observed both with direct supplementation and when the gut microbiome was altered to produce more glutamic acid.
What this could mean in practice
The results come from animal studies. Whether the same effects occur in humans has not yet been demonstrated. But the research adds a concrete link between the gut microbiome and cellular aging.
The idea that egg health can be influenced through the gut, rather than only through hormonal or genetic pathways, is relatively new. It points toward interventions that may slow reproductive aging.