Microbiome Bites December 11th 2016: Microbiome Implicated in HIV and Alzheimer’s Disease

Microbiome HIV

1. The Vaginal Microbiome and HIV Infection Risk

In southern and eastern Africa alone, an estimated 380,000 young women (16-24) contract HIV each year, making them up to four times more likely to be infected with HIV than their male counterparts. Reducing new HIV infections in young women is one of the greatest challenges in southern Africa.

Clinical trial data has shown that vaginal inflammation accurately predicts which women will get infected with HIV, leading researchers to question whether differences in the populations of bacteria, fungi, or other vaginal microbes might be driving the inflammation.

Examining the genetic profiles of vaginal microorganisms sampled from 119 women researchers found that women who had the bacterium Prevotella bivia in their vaginas were 19 times more likely to have vaginal inflammation and almost 13 times more likely to contract HIV. Interestingly, some other bacteria appeared to have a protective effect: women with Megasphaera and BVAB-1 were 10 times less likely to acquire the disease.

Managing bacteria to reduce vaginal inflammation could be a cost-effective way to curb the spread of HIV in low-income countries hardest hit by the epidemic. Read more.

2. Bacterial proteins may influence Alzheimer's disease pathology

Scientists have known for some time that infections can increase the risk of Alzheimer's disease. Now for the first time researchers at University of California Davis have shown that proteins from gram-negative bacteria are associated with beta amyloid plaques in Alzheimer’s. These are the first bacterial molecules that are consistently found in all brains. Finding a proven link between bacterial infections and Alzheimer's could offer new opportunities to prevent and treat the disease.

The study is published in the journal Neurology.

3. Taking probiotics may help you manage stress and anxiety more effectively

University of Missouri researchers are focusing on the mental health benefits of probiotics. Their research suggests that a common probiotic found in supplements and yogurt may help to decrease stress-related behavior and anxiety. Their research uses a zebrafish model for neurological diseases.

The researchers subjected the fish to various natural stresses, such as overcrowding, in the presence or absence of the probiotic strain Lactobacillus plantarum. Afterwards, the researchers analyzed the gene pathways of both groups of fish, finding that fish in the supplement-provided tanks showed a reduction in the metabolic pathways associated with stress.

The full article is published in the journal Scientific Reports.