# Glycogen in bacterial Vaginosis & How Carbohydrates Shape the Vaginal Microbiome

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2021 · $394,896

## Abstract

SUMMARY
Bacterial vaginosis (BV) is associated with higher risks of a dozen or more serious health complications.
Unfortunately, antibiotic treatment is only effective for temporarily alleviation of BV. Microbiological and
biochemical signatures of BV have been studied at length in relation to the `healthy' vaginal microbiome
dominated by lactobacilli. However, little is known about the metabolism of many fastidious vaginal bacteria,
how the metabolism of carbohydrates may drive bacterial growth, or how metabolic function of different
bacteria may drive the compositions of bacterial communities and the physiology of the vagina. Such gaps in
our understanding prevent the development of rational strategies to deter BV bacteria and encourage
lactobacilli in the vagina. This proposal uses new experimental models of human vaginal community dynamics
with the overarching goal of defining the carbohydrate preferences of vaginal bacteria. By measuring the
growth and metabolic output of bacteria in mono-culture, and within ex vivo vaginal microbial communities, our
broader objective is to develop conditions that specifically discourage BV bacteria and favor lactobacilli. In
three specific aims, this proposal will use a combination of tools in microbiology and biochemistry together with
genomics and proteomics to investigate the carbohydrate preferences of vaginal bacteria and potential
mechanisms that can change in the composition and metabolism of vaginal communities. Glycogen is one
example of an abundant potential source of carbohydrates in the vagina. As a polymer of glucose, glycogen is
believed to be a carbon source for `healthy' lactobacilli. However, this interpretation has been based largely on
correlative data rather than experimental investigation of the metabolic behaviors of vaginal bacteria. We
present evidence that glycogen metabolism can fuel the outgrowth of specific BV bacteria and can lead to
depletion of glycogen in culture. In Aim 1, we will examine which bacteria found in the vagina can employ
amylases to metabolize glycogen, and we will define the relevant biochemical activities and identities of
glycogen-cleaving enzymes. In Aim 2, we will investigate the larger role of glycogen metabolism for vaginal
community dynamics, testing the hypothesis that glycogen supports the growth of bacteria in cultured BV
communities, and that the inhibition of glycogen metabolism limits the expansion of BV-associated bacterial
communities. Finally, in Aim 3, we will comprehensively investigate the carbohydrate preferences of vaginal
bacteria, with particular emphasis on selectively promoting the growth and metabolism of lactobacilli. The
successful completion of these aims will have an important positive impact on this field by establishing
mechanistic insights about how BV bacteria utilize potential carbohydrate carbon sources available in the
vagina. Furthermore, successful completion of these studies will lead to important insights about how to us...

## Key facts

- **NIH application ID:** 10250560
- **Project number:** 5R01AI127554-05
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Warren G Lewis
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $394,896
- **Award type:** 5
- **Project period:** 2017-06-07 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10250560

## Citation

> US National Institutes of Health, RePORTER application 10250560, Glycogen in bacterial Vaginosis & How Carbohydrates Shape the Vaginal Microbiome (5R01AI127554-05). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10250560. Licensed CC0.

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