Bloating in Women: Hormonal, Functional, and Microbiome Considerations

Bloating is an uncomfortable gastrointestinal (GI) symptom that affects almost everyone. GI symptoms and bloating in women are more common due to fluctuations in hormone levels, which can lead to altered digestion and fluid retention throughout the month¹. Understanding the intricate communication between the female gut microbiome and these hormonal cycles is key to finding relief. Read on to explore the influence of the relationship between bloating, the gut microbiome and hormones, and how specific probiotics for bloating may help restore digestive balance.

Feeling bloated and tired: differential diagnosis

Bloating and fatigue are common symptoms that can have many explanations.

Digestive issues such as irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO) are particularly common in women, and both often cause bloating². In IBS, miscommunication between the gut and brain, which is heavily influenced by the gut microbiome, can lead to bloating and fatigue³. SIBO, on the other hand, happens when there is an imbalance between beneficial and harmful gut bacteria, leading to fermentation, gas and discomfort, which may also affect energy levels through the gut–brain axis⁴.

Iron deficiency, another common issue among women, can add to this mix, bringing fatigue and digestive symptoms⁵. Similarly, low thyroid function slows metabolism and often causes bloating and sluggishness⁶.

Hormonal conditions such as endometriosis can also mimic digestive bloating by trapping gas and triggering inflammation⁷. Premenstrual syndrome (PMS) may lead to temporary bloating due to hormone-driven fluid retention and slower digestion⁸.

Although these causes are often manageable and not usually serious, new or rapidly worsening bloating, abdominal pain, unexplained weight loss, changes in bowel habits, or shifts in menstrual patterns should prompt closer medical assessment.

Hormonal influences across the menstrual cycle

Hormonal changes throughout the menstrual cycle can have a real impact on digestion, bloating and energy levels.

The menstrual cycle can be broken down into menstruation (shedding of the uterine lining), the follicular phase (growth of new follicles), ovulation (egg release), and the luteal phase (preparing for pregnancy). Each phase is associated with different oestrogen and progesterone levels⁹.

During the luteal phase, progesterone levels rise, which can cause water retention, slowed digestion, bloating and constipation. Premenstrual changes in appetite can also contribute to feeling bloated and tired¹⁰.

Tracking symptoms throughout several cycles can help identify patterns more clearly. This can make it easier to tell whether bloating or fatigue is driven by hormones or by something else, such as diet or gut health. Water intake, fibre intake and exercise can all be adjusted to ease digestive sluggishness and improve comfort.

What to take to relieve bloating: clinical options

If bloating is not due to hormonal fluctuation or illness, there are many practical ways to help ease discomfort. The best solution for bloating in females often depends on the underlying cause, which means a combination of dietary changes, lifestyle adjustments and, sometimes, medication may be helpful.

One of the first ways to help with bloating is to adjust the diet. Increasing fibre supports digestion and keeps bowel movements regular. Fibre supplements can also be helpful. However, the type of fibre is important, since some people find that introducing high-fibre foods suddenly can make bloating worse. The best approach is to introduce fibre gradually¹¹.

FODMAPs are certain carbohydrates that are poorly absorbed in the gut. The gut microbiome then ferments them, producing gas and resulting in bloating. These include some fruits, dairy, wheat, beans and pulses. Choosing lower-FODMAP foods may help relieve bloating symptoms, especially in IBS¹².

Medications such as antispasmodics can be helpful because they relax the muscles in the digestive tract, reducing cramping and discomfort¹³. Digestive enzymes can support food breakdown and reduce gas build-up¹⁴. Simethicone is an over-the-counter treatment that works by easing the passage of gas and reducing build-up¹⁵. Prebiotics and probiotics may also help support a healthier gut microbiome balance, which can help manage bloating.

It is important to recognise when further medical advice is needed. New or severe bloating, unexplained weight loss, changes in bowel habits, or ongoing abdominal pain should prompt a conversation with a healthcare professional to rule out more serious causes.

The female gut microbiome

The link between a gut microbiome that favours harmful bacteria (dysbiosis) and illness in women is well documented¹⁷. The oestrobolome is a collection of gut bacteria that regulate oestrogen metabolism by producing enzymes such as β-glucuronidase. These help the gut reabsorb oestrogen and maintain overall hormonal balance. Disruptions to the oestrobolome, such as dysbiosis, can affect hormone levels¹⁸.

Compared with men, the female gut microbiome may contain more oestrobolome-related activity, but there is limited evidence to suggest the two are hugely different overall. There appears to be more variation between individuals based on lifestyle and diet than by sex alone¹⁹.

Animal models studying differences between males and females have shown that the female gut microbiome may be more sensitive to antibiotics than the male microbiome²⁰. However, there are not many human studies to confirm this. Hormonal contraception may also influence the gut microbiome by slightly reducing its abundance and balance, although more research is needed²¹.

Probiotic interventions for female bloating

Multiple clinical studies suggest that probiotics may help reduce bloating. However, it is important to note that all of these studies, except study 2, involved both men and women. While the results were not always reported separately by sex, the findings are still relevant because the probiotic groups included either an equal number of men and women or more women overall.

Single-strain probiotic treatments

• Bifidobacterium longum 35624: After an 8-week course, participants reported an approximately 43% reduction in IBS symptoms²².
• Bifidobacterium infantis 35624: After 4 weeks, women with IBS reported significant improvements in bloating, bowel movements and gas²³.
• Lactobacillus plantarum 299v: Adults with IBS reported improved quality of life and reduced bloating after 4 weeks of daily supplementation²⁴.
• Bacillus coagulans: Eight weeks of daily use improved IBS symptoms and bloating, with benefits continuing for 30 days after the study ended²⁵.

Multi-strain probiotic treatments

• Bifidobacterium longum CECT 7347 (ES1) and heat-treated Bifidobacterium longum CECT 7347 (HT-ES1): Daily probiotic and postbiotic supplementation improved IBS symptoms, stool consistency, quality of life, abdominal pain severity and anxiety scores over 84 days²⁶.
• Bifidobacterium longum, Bifidobacterium infantis, Bifidobacterium breve, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus plantarum, and Streptococcus salivarius subsp. thermophilus: Over 8 weeks of twice-daily probiotics, participants experienced improvements in flatulence and gassiness²⁷.
• Multi-species synbiotic probiotic containing 25 Bifidobacterium, Lactiplantibacillus, Lacticaseibacillus, Lactobacillus, Limosilactobacillus, and Ligilactobacillus species: In healthy individuals, 6 weeks of daily supplementation improved gastrointestinal quality of life, bloating, gas, abdominal discomfort and bowel habits²⁸.

Dietary probiotic treatments

• Bifidobacterium animalis subsp. lactis, Streptococcus salivarius subsp. thermophilus, and Lactobacillus delbrueckii subsp. bulgaricus in yoghurt: Adults with IBS noted that twice-daily consumption reduced IBS symptoms, eased bloating, flatulence and general pain, and improved bowel habits²⁹.
• Bacillus velezensis BV379: Daily intake over 8 weeks improved bloating and gassiness³⁰.
• Lactobacillus plantarum nF1-supplemented kimchi: Abdominal pain or inconvenience, desperation, incomplete evacuation and bloating all improved after 12 weeks of daily kimchi intake. Beneficial changes were also observed in microbiome composition³¹.

Clinical takeaways

Bloating in women can happen for many reasons, often overlapping in complex ways. To manage bloating effectively, it helps to identify the main factors driving symptoms. Hormonal cycles and dietary habits can both influence bloating, but paying attention to what is normal for the individual can guide the most appropriate approach.

Probiotics show promise for easing bloating, although there are some caveats. While there is strong research supporting probiotics for bloating and IBS in general, very few studies focus specifically on women. Some later analyses suggest that women may experience a better response to treatments such as probiotics compared with men, but more research is needed to confirm these findings³².

References

1. Iovino P, Bucci C, Tremolaterra F, Santonicola A, Chiarioni G. Bloating and functional gastro-intestinal disorders: where are we and where are we going? World J Gastroenterol. 2014;20(39):14407–19.
2. Ghoshal UC, Shukla R, Ghoshal U. Small intestinal bacterial overgrowth and irritable bowel syndrome: a bridge between functional organic dichotomy. Gut Liver. 2017;11(2):196–208.
3. Raskov H, Burcharth J, Pommergaard HC, Rosenberg J. Irritable bowel syndrome, the microbiota and the gut-brain axis. Gut Microbes. 2016;7(5):365–83.
4. Rao SSC, Rehman A, Yu S, Andino NM de. Brain fogginess, gas and bloating: a link between SIBO, probiotics and metabolic acidosis. Clin Transl Gastroenterol. 2018;9(6):162.
5. Özbilen M, Kaya Y. Beyond anaemia: a comprehensive analysis of iron deficiency symptoms in women and their correlation with biomarkers. BMC Womens Health. 2025;25(1):376.
6. Grixti L, Fisher H, Priestley J, McMullan C, Woollven A, Perros P, et al. Prevalence and severity of fatigue in treated hypothyroidism: results of a UK survey. Eur Thyroid J. 2025;14(3):e250044.
7. Velho RV, Werner F, Mechsner S. Endo belly: what is it and why does it happen? A narrative review. J Clin Med. 2023;12(22):7176.
8. Martin BR, Woodruff J. Management of a patient with premenstrual syndrome using acupuncture, supplements and meditation: a case report. J Chiropr Med. 2023;22(3):222–9.
9. Thiyagarajan DK, Basit H, Jeanmonod R. Physiology, menstrual cycle. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2026.
10. Early- and late-luteal-phase oestrogen and progesterone levels of women with premenstrual dysphoric disorder. PMC.
11. Zhang M, Juraschek SP, Appel LJ, Pasricha PJ, Miller ER, Mueller NT. Effects of high-fibre diets and macronutrient substitution on bloating: findings from the OmniHeart trial. Clin Transl Gastroenterol. 2020;11(1):e00122.
12. Bogdanowska-Charkiewicz D, Malinowska U, Daniluk J. An umbrella review of meta-analyses on the low-FODMAP diet in IBS. Front Nutr. 2025;12:1714281.
13. Stoyanova M, Milusheva M, Gledacheva V, Stefanova I, Todorova M, Kircheva N, et al. Spasmolytic activity and anti-inflammatory effect of novel mebeverine derivatives. Biomedicines. 2024;12(10):2321.
14. Ullah H, Di Minno A, Piccinocchi R, Buccato DG, De Lellis LF, Baldi A, et al. Efficacy of digestive enzyme supplementation in functional dyspepsia: a monocentric, randomised, double-blind, placebo-controlled clinical trial. Biomed Pharmacother. 2023;169:115858.
15. Petrisor DC, Etropolska Z, Elenski K, Dimitrova E, Santos J. Efficacy and safety of pea protein and xyloglucan versus simethicone in functional abdominal bloating and distension. Dig Dis Sci. 2024;69(1):161–8.
16. Mishra AP, Marrelli LM, Bonner-Reid FT, Shekhawat P, Toney R, Benipal IK, et al. Gut-brain axis: understanding the interlink between alterations in the gut microbiota and autism spectrum disorder. Cureus. 2025;17(7):e88579.
17. 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.
18. 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.
19. Valeri F, Endres K. How biological sex of the host shapes its gut microbiota. Front Neuroendocrinol. 2021;61:100912.
20. Gao H, Shu Q, Chen J, Fan K, Xu P, Zhou Q, et al. Antibiotic exposure has sex-dependent effects on the gut microbiota and metabolism of short-chain fatty acids and amino acids in mice. mSystems. 2019;4(4):e00048-19.
21. Mihajlovic J, Leutner M, Hausmann B, Kohl G, Schwarz J, Röver H, et al. Combined hormonal contraceptives are associated with minor changes in composition and diversity in gut microbiota of healthy women. Environ Microbiol. 2021;23(6):3037–47.
22. Lenoir M, Wienke J, Fardao-Beyler F, Roese N. An 8-week course of Bifidobacterium longum 35624 is associated with a reduction in the symptoms of irritable bowel syndrome. Probiotics Antimicrob Proteins. 2025;17(1):315–27.
23. Whorwell PJ, Altringer L, Morel J, Bond Y, Charbonneau D, O’Mahony L, et al. Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome. Am J Gastroenterol. 2006;101(7):1581–90.
24. Ducrotté P. Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome. World J Gastroenterol. 2012;18(30):4012.
25. Sudha MR, Jayanthi N, Aasin M, Dhanashri RD, Anirudh T. Efficacy of Bacillus coagulans Unique IS2 in treatment of irritable bowel syndrome in children: a double-blind, randomised placebo-controlled study. Benef Microbes. 2018;9(4):563–72.
26. Srivastava S, Basak U, Naghibi M, Vijayakumar V, Parihar R, Patel J, et al. A randomised double-blind, placebo-controlled trial to evaluate the safety and efficacy of live Bifidobacterium longum CECT 7347 (ES1) and heat-treated Bifidobacterium longum CECT 7347 (HT-ES1) in participants with diarrhoea-predominant irritable bowel syndrome. Gut Microbes. 2024;16(1):2338322.
27. Kim HJ, Vazquez Roque MI, Camilleri M, Stephens D, Burton DD, Baxter K, et al. A randomised controlled trial of a probiotic combination VSL#3 and placebo in irritable bowel syndrome with bloating. Neurogastroenterol Motil. 2005;17(5):687–96.
28. Allegretti JR, Kassam Z, Kelly CR, Grinspan A, El-Nachef N, Van Den Elzen C, et al. A randomised, placebo-controlled trial evaluating multi-species synbiotic supplementation for bloating, gas and abdominal discomfort. Nutrients. 2026;18(2):255.
29. Roberts LM, McCahon D, Holder R, Wilson S, Hobbs FR. A randomised controlled trial of a probiotic functional food in the management of irritable bowel syndrome. BMC Gastroenterol. 2013;13:45.
30. Garvey SM, Blonquist TM, Brutscher LM, Walsh DM, Kaden VN, Beckman DB, et al. Dietary supplementation with the probiotic Bacillus velezensis BV379 decreases abdominal bloating without perturbing the commensal gut microbiota: a randomised, double-blind, placebo-controlled trial in healthy adults. J Am Nutr Assoc. 2026;45(3):250–65.
31. Kim HY, Park ES, Choi YS, Park SJ, Kim JH, Chang HK, et al. Kimchi improves irritable bowel syndrome: results of a randomised, double-blind placebo-controlled study. Food Nutr Res. 2022;66:8268.
32. van Kessel L, Teunissen D, Lagro-Janssen T. Sex-gender differences in the effectiveness of treatment of irritable bowel syndrome: a systematic review. Int J Gen Med. 2021;14:867–84.