Eggs and Gut Heath

Gut Decisions: Eggs, Microbiome and Cognition

One of the most significant advances in nutrition research over recent years has been growth in understanding of the role the gut microbiome plays in maintaining and promoting good health and well-being. This is related to both the health of the gut itself, and the link between a healthy gut and a healthy mind.

While some research indicates eggs may play a role in this area, we were keen to find out more.

As a result, Australian Eggs partnered up with the University of Melbourne to conduct a randomised controlled trial investigating the effects of eating two eggs a day for six weeks on gut microbiome health and cognitive function. Different age groups were assessed including both younger adults (18–40) and older adults (65+).

The research found that eating eggs regularly improves measures of gut health. For practical applications in your clinic or consultations, download our gut health meal plan. But first, here’s some background.

How Are Eggs Related to Gut Health?

When the researchers reviewed existing studies to provide the initial background work to inform the design of the new study, they found that dietary protein, as found in eggs, is linked to microbial diversity. Similarly, some of the key nutrients in eggs, such as choline and tryptophan, are key players in this area.

However, they also found few human studies had been conducted with most egg-gut research being done on animals or being based on observational studies (which don’t prove cause and effect).

With this information at hand, we set about testing whether eating eggs regularly, at different stages of the lifecycle, would influence gut microbiota and cognitive function.

Inflammatory markers were also tested to explore potential mechanistic pathways through which egg consumption might influence gut health, cognition, and overall health.

Study Design and Methodology

A randomised controlled trial design was used to evaluate the impact of consuming two eggs daily for six weeks on gut microbiota and cognitive outcomes.

Participants included 136 healthy adults, divided into younger (18–40 years) and older (≥ 65 years) cohorts.
Participants were randomised to either consume two eggs per day or avoid eggs.
Assessments included gut microbiome analysis, cognitive performance tasks, and inflammatory marker analysis.

Results

Key Findings on Gut Microbiome

The research found that egg consumption positively influences gut microbiome stability and composition.

Participants who ate eggs maintained a more stable microbial richness and evenness over time compared to those who didn’t eat eggs.
Significant differences in microbial composition were observed, particularly an increase in the beneficial bacterial group called Megamonas, a type that has been linked to reduced metabolic disease risk.
Analysis of diversity showed the differences between egg consumers and non-consumers were statistically significant.
Results were observed across both age groups, with a greater response in gut microbiome changes seen in older adults.

Cognitive Function Outcomes

Regular egg consumption did not negatively impact cognitive performance across various tests in both age groups however, it also found no significant improvements. The study suggests that consuming two eggs daily is safe and maintains cognitive function in healthy adults.

Inflammatory Marker Analysis

Inflammation is a key factor in gut-brain signalling and overall health. Results of the testing found inflammatory markers remained stable across both age groups, indicating no adverse effects from egg consumption.

Conclusion

Overall, the findings suggest that regular egg intake may enhance gut microbiome stability, a contributing factor to better digestive health. Egg intake increases the presence of beneficial bacteria like Megamonas, which in turn has been linked to a reduced risk of diabetes and obesity. There was no change to cognitive function or inflammatory markers.

Overall

Eggs are a nutrient-dense, gut-friendly food.
Two eggs a day can have beneficial effects on the gut microbiome, particularly in older adults.
Eggs are easy and versatile to include in the diet daily.
Enjoying eggs with fibre-rich whole foods may have even greater effects for gut health.
Eating eggs regularly is a practical way to support gut health across the lifespan.

This statement is for healthcare professionals only.