# Mechanisms and consequences of human milk oligosaccharide growth and bile stress across diverse strains of the potential therapeutic bacterium, Akkermansia muciniphila.

> **NIH NIH SC1** · CALIFORNIA STATE UNIVERSITY NORTHRIDGE · 2022 · $362,500

## Abstract

The current paradigm that Akkermansia muciniphila is a beneficial member of the human gut
microbiome is based on an incomplete understanding of the physiological diversity and mechanistic activity
across the lineage, as all previous work has focused on one described strain. The long-term goal is to help
develop targeted, therapeutic uses of Akkermansia, either through stimulating endogenous strains with
prebiotics or by administering specific strains as probiotics. The overall objectives for this application are to
characterize the molecular mechanisms and immunogenic properties of genomically diverse strains of
human-associated Akkermansia grown (i) on human milk oligosaccharides (HMO) and (ii) in the presence of
bile. The central hypothesis of this work is that human-associated Akkermansia have evolved different growth
efficiencies on HMO and bile stress responses that shape their immunogenic potential in a strain dependent
manner. The rationale for this work is that if we are to use Akkermansia for the therapeutic treatment of
metabolic disorders or other gastrointestinal diseases, then we need to design biologically informed treatment
strategies that promote or introduce select strains for optimal health outcomes. The central hypothesis will be
tested by pursuing two specific aims: 1) Identify the molecular mechanisms and immunogenic properties of
Akkermansia grown on HMO; 2) Identify the bile resistance mechanisms and immunogenic properties of
Akkermansia grown in the presence of bile. Under the first aim, targeted gene expression studies coupled
with cloning and functional assays will be used to identify glycoside hydrolase enzymes involved in growth on
HMO in three genomically diverse Akkermansia isolates. Concurrently, targeted metabolomics analyses will
be used to quantify HMO consumption and fermentation end products. Lastly, co-culture experiments with
HMO grown Akkermansia cells and human epithelial cells will be used to measure bacterial binding efficiency
and the immune response of the epithelial cells. For the second aim, transcriptomic and proteomic profiling,
coupled with targeted metabolomics (i.e. bile acid composition and microbial extracellular polysaccharides)
will be used to characterize the bile stress response of the three Akkermansia isolates. Similar to aim 1, co-
culture experiments with bile grown Akkermansia strains and human epithelial cells be used to measure
bacterial binding efficiency and the host immune response. The research proposed in this application is
innovative because it represents a substantive departure from the status quo by providing insights into the
physiological diversity and molecular mechanisms across the Akkermansia lineage. The proposed research
is significant because it will help define the physiological landscape across the lineage, thereby opening new
horizons for biologically informed treatment strategies that promote or introduce select Akkermansia strains
for optimal health outcomes.

## Key facts

- **NIH application ID:** 10436303
- **Project number:** 5SC1GM136546-03
- **Recipient organization:** CALIFORNIA STATE UNIVERSITY NORTHRIDGE
- **Principal Investigator:** Gilberto Flores
- **Activity code:** SC1 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $362,500
- **Award type:** 5
- **Project period:** 2020-07-09 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10436303

## Citation

> US National Institutes of Health, RePORTER application 10436303, Mechanisms and consequences of human milk oligosaccharide growth and bile stress across diverse strains of the potential therapeutic bacterium, Akkermansia muciniphila. (5SC1GM136546-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10436303. Licensed CC0.

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