Menstrual Bloating, Fatigue, and Period Pain - Nutritional and Microbiome Perspectives

Menstrual bloating, fatigue and period pain are common issues that can significantly impact daily life. Nutrition and the gut microbiome may play a role in managing these symptoms. Read on to explore how dietary strategies and probiotics could help support relief and overall menstrual health.

Hormonal changes across the menstrual cycle

The menstrual cycle is governed by changes in oestrogen and progesterone levels and can be broken into four stages¹:

• Menstruation.
• The follicular phase.
• Ovulation.
• The luteal phase.

When pregnancy does not occur, oestrogen and progesterone levels drop sharply, triggering the release of inflammatory chemicals called prostaglandins. If prostaglandin levels are too high, contractions become so intense that they cut off oxygen supply to the uterine tissue, resulting in the sharp, cramping pain known as primary dysmenorrhoea². Prostaglandins circulate throughout the bloodstream and affect the whole body. When they reach the digestive tract, they can stimulate contraction and lead to other symptoms of primary dysmenorrhoea, such as nausea, bloating and diarrhoea³.

At the same time, changes in oestrogen and progesterone levels can affect the brain’s hormonal balance, leading to changes in mood, disturbed sleep, lethargy, irritability and even headaches that are often accompanied by physical cramps⁴.

Menstrual bloating relief: mechanisms

During the luteal phase, the time between ovulation and menstruation, the body experiences a significant rise in progesterone. While this hormone is essential for preparing the womb, it also acts as a muscle relaxant for the rest of the body, including the digestive tract⁵. This slows digestion, which can cause water retention, bloating and constipation. It can also lead to gas build-up as the gut microbiome has more time to ferment food, which further contributes to bloating⁶.

There is a difference between hormonal bloating, which changes throughout the menstrual cycle, and other bloating, which may be constant. Non-hormonal bloating may indicate underlying conditions such as irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO), iron deficiency or low thyroid function⁷.

For a comprehensive breakdown of these differential diagnoses and options for relief, read our guide on Bloating in women: hormonal, functional, and microbiome considerations.

How long does bloating last in a period?

Bloating and other gastrointestinal symptoms often occur towards the end of the luteal phase. As the cycle transitions into early menstruation, these symptoms often peak⁸, as prostaglandins cause the gut to become hyperactive. This contributes to cramps, nausea, bloating and diarrhoea. Fortunately, as prostaglandin levels decrease, these symptoms usually subside within the first three to four days of the period⁹.

However, persistent or severe bloating that remains constant throughout the month, or is accompanied by unexplained weight loss or significant changes in bowel habits, may be due to other issues such as IBS or SIBO.

Extreme fatigue during period: contributing factors

Fatigue is a common symptom experienced during a period, and it can have many causes:

• Blood and iron levels: Blood loss during menstruation can lower iron levels and cause temporary anaemia, which is associated with brain fog, fatigue and heavy limbs¹⁰.
• Sleep disturbances: Altered hormone levels can affect body temperature and contribute to sleep disturbance, leaving the body exhausted¹¹.
• Neurotransmitter changes: Fluctuating oestrogen and progesterone levels affect neurotransmitters such as serotonin and dopamine, which regulate mood and can contribute to lethargy¹².

Best food for period cramps

Diet may play a role in managing dysmenorrhoea symptoms. Omega-3 fatty acids, found in foods such as oily fish and nuts, have been shown to reduce prostaglandin production and may help alleviate menstrual pain¹³. Magnesium-rich foods, including dark chocolate, leafy greens and seeds, may support muscle relaxation and reduce cramping¹⁴.

Emerging research also suggests that the gut microbiome and overall dietary patterns may influence inflammation and hormone regulation, although this relationship is still being explored. Maintaining stable blood sugar through complex carbohydrates may support overall metabolic health, which could indirectly influence symptoms¹⁵.

The gut–hormone axis

Gut health and hormones are intrinsically linked. The gut–brain axis is known to affect mood and has a large impact on hormone signalling throughout the body. Specifically, the gut microbiome contains the oestrobolome, a collection of gut bacteria that regulate oestrogen metabolism. The oestrobolome produces enzymes that help the gut reabsorb and recycle oestrogen¹⁶.

If the gut microbiome or oestrobolome is disturbed, known as dysbiosis, this can lead to altered oestrogen cycling, which may further imbalance hormone levels and worsen dysmenorrhoea¹⁷.

Probiotics and menstrual symptoms

Several studies have examined how specific probiotic strains may help alleviate menstrual symptoms by supporting gut health, modulating inflammation and influencing hormone balance.

• Lactobacillus gasseri CP2305: Daily supplementation led to fewer symptoms of premenstrual syndrome compared with the control group, particularly self-reported depressed mood and anxiety¹⁸.
• Lactobacillus paragasseri OLL2809: In women aged 25 to 40, supplementation lowered reports of premenstrual irritability after three menstrual cycles compared with placebo¹⁹.
• Multistrain probiotics containing six strains of Lactobacillus and Bifidobacterium: Twice-daily supplementation for three months improved mental health scores and reduced the use of non-steroidal anti-inflammatories for pain management compared with placebo²⁰.
• Lactiplantibacillus plantarum Probio87: After six weeks of daily supplementation, women reported improved general health, mood, anxiety and sleep²¹.
• Bifidobacterium longum OLP-01, Lactobacillus plantarum PL-02 and Lactococcus lactis LY-66: Women with dysmenorrhoea found that combining high-intensity exercise with probiotics for 10 weeks supported hormone balance, reduced inflammation and eased cramps. Exercise and probiotics alone also showed benefits, but combined treatment outperformed both²².
• Prebiotic- and probiotic-rich yoghurt: In women aged 45 to 55, 100 g of probiotic yoghurt every day for six weeks significantly improved self-reported stress, anxiety and quality-of-life scores compared with control groups²³.
• Multistrain probiotics containing five strains of Lacticaseibacillus, Limosilactobacillus, Lactobacillus and Bifidobacterium: Women were given daily probiotics for six months and reported better hormonal balance and menstrual symptoms compared with the control group²⁴.
• Bifidobacterium animalis lactis BB-12: After eight weeks of daily supplementation, healthy women taking the combined oral contraceptive pill had reduced abdominal pain, fewer digestive symptoms, less stress and a more stable oestrobolome compared with the control group²⁵.
• Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium bifidum: Women with polycystic ovary syndrome (PCOS) were supplemented for 12 weeks and experienced improved hormonal balance, lower levels of inflammation and oxidative stress, and improved insulin resistance²⁶.
• Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14: These probiotics were shown to migrate through the intestinal tract and help colonise the vaginal tract, improving vaginal flora and menstrual discomfort²⁷.

Clinical takeaways

Menstrual symptoms are influenced by many different factors, including changes in hormones, inflammation in the body and communication between the gut and brain. The gut microbiome may also play a role in how severe symptoms feel. Because of this, diet and nutrient levels are important.

Managing dysmenorrhoea works best when it is personalised, taking into account each individual’s underlying health and lifestyle factors. Probiotics may help by supporting gut health, reducing inflammation and potentially improving mood, alongside usual treatments²⁸.

Overall, a combined approach that focuses on nutrition, lifestyle habits and possibly probiotics may help make menstrual symptoms easier to manage.

References

1. Thiyagarajan DK, Basit H, Jeanmonod R. Physiology, menstrual cycle. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2026.
2. Liggins GC. Prostaglandins: current therapeutic status in obstetrics. Drugs. 1974;8(3):161–3.
3. Budoff PW. The use of prostaglandin inhibitors for the premenstrual syndrome. J Reprod Med. 1983;28(7):469–78.
4. Handy AB, Greenfield SF, Yonkers KA, Payne LA. Psychiatric symptoms across the menstrual cycle in adult women: a comprehensive review. Harv Rev Psychiatry. 2022;30(2):100–17.
5. White CP, Hitchcock CL, Vigna YM, Prior JC. Fluid retention over the menstrual cycle: 1-year data from the prospective ovulation cohort. Obstet Gynecol Int. 2011;2011:138451.
6. Wei L, Singh R, Ro S, Ghoshal UC. Gut microbiota dysbiosis in functional gastrointestinal disorders: underpinning the symptoms and pathophysiology. JGH Open. 2021;5(9):976–87.
7. Dukowicz AC, Lacy BE, Levine GM. Small intestinal bacterial overgrowth. Gastroenterol Hepatol. 2007;3(2):112–22.
8. Mendelson S, Anbukkarasu P, Cassisi JE, Zaman W. Gastrointestinal functioning and menstrual cycle phase in emerging young adult women: a cross-sectional study. BMC Gastroenterol. 2023;23:406.
9. Dawood MY. Dysmenorrhoea and prostaglandins: pharmacological and therapeutic considerations. Drugs. 1981;22(1):42–56.
10. Fernandez-Jimenez MC, Moreno G, Wright I, Shih PC, Vaquero MP, Remacha AF. Iron deficiency in menstruating adult women: much more than anaemia. Womens Health Rep. 2020;1(1):26–35.
11. Jehan S, Auguste E, Hussain M, Pandi-Perumal SR, Brzezinski A, Gupta R, et al. Sleep and premenstrual syndrome. J Sleep Med Disord. 2016;3(5):1061.
12. Barth C, Villringer A, Sacher J. Sex hormones affect neurotransmitters and shape the adult female brain during hormonal transition periods. Front Neurosci. 2015;9:37.
13. Snipe RMJ, Brelis B, Kappas C, Young JK, Eishold L, Chui JM, et al. Omega-3 long chain polyunsaturated fatty acids as a potential treatment for reducing dysmenorrhoea pain: systematic literature review and meta-analysis. Nutr Diet. 2024;81(1):94–106.
14. Fatima G, Dzupina A, B Alhmadi H, Magomedova A, Siddiqui Z, Mehdi A, et al. Magnesium matters: a comprehensive review of its vital role in health and diseases. Cureus. 2024;16(10):e71392.
15. Jyoti, Dey P. Mechanisms and implications of gut microbial modulation of intestinal metabolic processes. NPJ Metab Health Dis. 2025;3(1):24.
16. Hu S, Ding Q, Zhang W, Kang M, Ma J, Zhao L. Gut microbial beta-glucuronidase: a vital regulator in female oestrogen metabolism. Gut Microbes. 2023;15(1):2236749.
17. Moustakli E, Stavros S, Katopodis P, Potiris A, Drakakis P, Dafopoulos S, et al. Gut microbiome dysbiosis and its impact on reproductive health: mechanisms and clinical applications. Metabolites. 2025;15(6):390.
18. Nishida K, Sawada D, Yasui T, Kuwano Y, Rokutan K. Daily intake of Lactobacillus gasseri CP2305 ameliorates psychological premenstrual symptoms in young women: a randomised, double-blinded, placebo-controlled study. J Funct Foods. 2021;80:104426.
19. Sato A, Fukawa-Nagira A, Sashihara T. Lactobacillus paragasseri OLL2809 improves premenstrual psychological symptoms in healthy women: a randomised, double-blind, placebo-controlled study. Nutrients. 2023;15(23):4985.
20. Zakaria IA, Mohammed Zain NA, Teik CK, Abu MA, Zainuddin AA, Abdul Aziz NH, et al. The role of probiotics in improving menstrual health in women with primary dysmenorrhoea: a randomised, double-blind, placebo-controlled trial. Womens Health. 2024;20:17455057241234524.
21. Nisaa AA, Mageswary U, Pei X, Kadir MN, Oon CE, Rajendran D, et al. Probiotic enhanced immunity and mental wellbeing of generally healthy women: a randomised, placebo-controlled and double-blind study. Benef Microbes. 2025;16(4):377–94.
22. Yang MY, Chen HY, Ho CH, Huang WC. Impact of probiotic supplementation and high-intensity interval training on primary dysmenorrhoea: a double-blind, randomised controlled trial investigating inflammation and hormonal modulation. Nutrients. 2025;17(4):622.
23. Shafie M, Homayouni Rad A, Mohammad-Alizadeh-Charandabi S, Mirghafourvand M. The effect of probiotics on mood and sleep quality in postmenopausal women: a triple-blind randomised controlled trial. Clin Nutr ESPEN. 2022;50:15–23.
24. Kaur I, Suri V, Sachdeva N, Rana SV, Medhi B, Sahni N, et al. Efficacy of multi-strain probiotic along with dietary and lifestyle modifications on polycystic ovary syndrome: a randomised, double-blind placebo-controlled study. Eur J Nutr. 2022;61(8):4145–54.
25. Judkins TC, Oula ML, Sims SM, Langkamp-Henken B. The effect of a probiotic on gastrointestinal symptoms due to menstruation in healthy adult women on oral contraceptives: randomised, double-blind, placebo-controlled trial protocol. Trials. 2022;23:481.
26. Karamali M, Eghbalpour S, Rajabi S, Jamilian M, Bahmani F, Tajabadi-Ebrahimi M, et al. Effects of probiotic supplementation on hormonal profiles, biomarkers of inflammation and oxidative stress in women with polycystic ovary syndrome: a randomised, double-blind, placebo-controlled trial. Arch Iran Med. 2018;21(1):1–7.
27. Morelli L, Zonenenschain D, Del Piano M, Cognein P. Utilisation of the intestinal tract as a delivery system for urogenital probiotics. J Clin Gastroenterol. 2004;38(Suppl 2):S107–10.
28. Patki A, Pandit S, Ashraf N, Makhwana S, Ghosh Dastidar B. Expert opinion on the use of probiotics in general gynaecological conditions. Cureus. 2025;17(3):e80875.