New research has strengthened the previous concept that gut bacteria can regulate the process of aging. The scientists of the study set out to check the link between the gut microbiota and the vascular aging.
Studying the Gut Bacteria and Vascular Health
The scientists administered a mixture of broad-spectrum antibiotics with poor absorption to a group of older mice and another group of younger mice. They added these antibiotics to the drinking water of these rodents for 3 to 4 weeks. This was to suppress their gut microbiota.
Next, the researchers have examined the health of their vascular systems by measuring the arterial stiffness as well as the health of the endothelium i.e. the layer of cells lining the inside of these arteries.
The team also took the blood samples for markers of inflammation as well as oxidative stress such as the free radicals.
Oxidative stress occurs when your body generates too many free radicals and have no antioxidants to degrade them. The studies have indicated that this may lead to cardiovascular disease, aging, and hypertension in general.
The researchers measured the amounts of nitric oxide, a compound that can expand the blood vessels. The researchers also examined the age-related changes in the guts of all the rodents.
By the end of the study, the scientists found that the old mice greatly benefitted from the antibiotic treatment whereas the older mice showed no effect.
How Old Age Impacts the Gut Health
The scientists set out to check certain age-related changes in the microbiome of these rodents. The purpose was to develop an understanding of how suppression of the microbiota can preserve the health.
To do this, they sequenced the fecal samples from the group of older mice and compared them with those having younger mice.
The older mice had an increased prevalence of microbes that were pro-inflammatory and had been previously associated with the disease. These include the microbes that had been previously linked with gut dysbiosis i.e. an imbalance between the friendly bacteria in the guts as well as the other pathogens.
For instance, a study has found that old mice had higher levels of Proteobacteria, a class of bacteria with famous pathogens like Salmonella, Campylobacter, and Escherichia coli.
The scientists also checked the blood plasma levels of trimethylamine N-oxide or TMAO. It is a type of metabolite produced when microorganisms in the gut break down the nutrients in the food.
The role of TMAO in chronic disease is uncertain. However, previous studies have linked high levels of TMAO in patients of kidney disease, cancer, and diabetes.
In the current study, the older mice had three times more TMAO in the blood as compared to the younger mice. The researchers established that antibiotic treatment suppressed the levels of this compound.
The scientists concluded the results saying that their study has provided sufficient evidence that gut microbiome is an important mediator of age-related arterial dysfunction as well as oxidative stress.