Your microbiome changes with your cycle. Hormonal fluctuations are linked to shifts in the composition of your gut flora. Most gut-health routines assume a fixed daily pattern, but research suggests your gut flora moves along with your cycle.

How it connects

Your cycle and your gut flora

Research points to a link between estrogen, progesterone, and which bacterial strains flourish in the gut. In the follicular phase (after your period), microbiome diversity tends to be higher in studies; in the luteal phase, a shift has been observed that some researchers suggest may relate to the bloated feeling many women experience premenstrually. This field of research is still relatively early in its development.

Diversity as a research theme

Scientists are examining whether a broader range of bacterial strains relates to how stable the system stays through change: cycle, life stage, or a demanding week. This is an active area of research, not an established fact.

Consistency and phase sensitivity

Research into building up gut flora points to the value of a daily foundation over a longer period. At the same time, some studies suggest that needs such as fibre, rest, and hydration may differ across cycle phases. What that means for you specifically is individual, and can't be drawn directly from these studies.

What's in Keanto Core

Core contains a broad spectrum of bacterial strains and prebiotic fibres.

This information is provided as general background and is not a medical claim. Food supplements are not a substitute for a varied diet.

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Sources

• Kasparek et al. (2024/2025). In vitro modeling of the female gut microbiome: effects of sex hormones and psychotropic drugs. Microbiology Spectrum. Read
• Vieira-Silva et al. (2022). Healthy female microbiome across body sites: effect of hormonal contraceptives and the menstrual cycle. Human Reproduction, Oxford Academic. Read
• Nuriel-Ohayon et al. (2019), cited in: Gut feeling: exploring the intertwined trilateral nexus of gut microbiota, sex hormones, and mental health. ScienceDirect (2024). Read
• Zoe Science & Nutrition (2025). Menopause and your gut microbiome: what happens? Read

Note: most research into sex hormones and the microbiome is still relatively young and partly based on animal or in-vitro models. The direction of the effect is well supported; the exact clinical implications per cycle phase are still very much in development.