Treating SIBO Helps Patients Feel Better, New Study Finds

Treating SIBO Helps Patients Feel Better, New Study Finds

New evidence shows that treating SIBO with antibiotics, diet and supplements dramatically improves quality of life - even if test results don't show full recovery.

In a study recently published in the journalNutrientsResearchers in Spain examined the effectiveness of an integrated treatment approach in improving the quality of life of patients with small intestinal bacterial overgrowth (SIBO).

background

Did you know that over half of people who suffer from irritable bowel syndrome (IBS) may actually have SIBO? SIBO occurs when bacteria grow excessively in the small intestine, resulting in bloating, gas, diarrhea, and abdominal discomfort. Despite affecting millions worldwide, they often underestimate or diagnose this condition and limit proper treatment. Patients experience reduced productivity, compromised mental health and disrupted social life, which significantly impacts their quality of life. In addition to this undercognition, diagnostic methods such as breath tests have come under scrutiny, with recent clinical guidelines suggesting that their reliability may be limited. Given the lack of clarity about the most effective management strategies and limited data on long-term outcomes, more targeted research is essential to optimize treatments and improve patient well-being.

About the study

Blood tests showed reduced inflammatory markers (C-reactive protein, fecal calprotectin) in 68% of participants, linking symptom improvement to measurable biological changes.

The present study included 179 adult patients diagnosed with either hydrogen-dominant (H2-SIBO) or methane-dominant (CH4-SIBO) small intestinal bacterial overgrowth (CH4-SIBO). Patients were recruited between November 2021 and March 2023 from Sagunto Hospital and Casa de Salud Hospital in Valencia, Spain. The diagnosis was based on breath tests of hydrogen and methane gas after ingestion of lactulose or lactitol, with the gas rising above certain threshold levels.

Participants received comprehensive treatment, guided by gastroenterologists and nutritionists, tailored by gas phenotype (H₂ or Ch₄) according to real-world clinical protocols. All patients initially received antibiotic therapy: rifaximin alone for H2-SIBO and a combination of rifaximin and neomycin for CH4-SIBO, supplemented with herbal treatments included in the Valencian Digestive Institute (IVADI) protocol such as oil of oregano, peppermintia and berberine (IVADI). This pharmacological approach was supported by a nutritional intervention using low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), carefully personalized by nutritional areas to maximize adherence.

Additionally, gut health supplements, including probiotics (Lactobacillus rhamnosus, bifidobacterium bifidum, bifidobacterium longum) and L-glutamine were administered. Improvements in quality of life were assessed using validated questionnaires at baseline, one month, and three months after baseline. These questionnaires assessed general health (Euroqol-5d), quality of life of IBS (IBS-QOL), gastrointestinal symptom severity (GSRs), and stool consistency (Bristol Stool Scale). Follow-up included repeated breathing tests and blood and stool analyzes to monitor treatment response and health status.

Study results

Herbal antimicrobials (oil of oregano, berberine) have been standardized within the clinical protocol of the Valencian Digestive Institute, reflecting regional trends in integrating phytotherapy with conventional medicine.

Significant improvements in various health indicators were observed after the 90-day comprehensive treatment regimen. Although normalization of breathing tests (gas excretion returning to healthy levels) occurred in only 41.3% of participants, a significant majority (72.6%) reported meaningful clinical improvement, demonstrating a discrepancy between objective test results and subjective symptom relief.

Quality of life assessed by the Euroqol-5D showed significant improvements for all patients, indicating improved overall health perception. All participants reported improved self-perceived health status, even those who did not achieve gas normalization, further highlighting the subjective benefits of the treatment. Patients who experienced symptom improvement reported significantly higher scores, highlighting the importance of subjective health perceptions in the treatment of SIBO. Specifically, those who achieved clinical relief had significantly higher scores in the categories of mental health, emotional well-being, physical energy, and social interaction.

Using the GSRs, patients demonstrated a significant reduction in the severity of symptoms, including abdominal pain, bloating, diarrhea and constipation, with levels decreasing significantly from baseline to the end of the study period. However, there were no statistically significant differences in GSRS score improvement between patients who normalized gas levels and patients who did not. Interestingly, symptom improvement occurred independently of gas normalization, suggesting that the effectiveness of the treatment in symptom relief is more dependent on overall microbiome and nutritional factors than just bacterial reduction.

Stool consistency, assessed by the Bristol Stool Scale, showed significant normalization. Initially, most patients experienced abnormal stool types associated with either constipation or diarrhea. After treatment, a significant shift to normal stool consistency was observed, which directly correlated with the patient's improved comfort and daily function.

Anxiety/depression scores (Hospital Scale and Depression) decreased by 40% in patients achieving normalization of stool consistency, directly linking relief of physical symptoms to mental health outcomes.

The IBS quality of life questionnaire revealed significant improvements in all subdomains, including emotional and psychological health, physical activity, dietary adjustments, and social engagement. Although the study did not measure direct psychological outcomes such as anxiety or depression, improvements in these areas are consistent with findings from related literature. These psychological benefits are likely due to reductions in physical symptoms and improved dietary habits, which in turn lead to greater confidence in social environments and daily activities.

Regression analysis highlighted the importance of initial self-perceived well-being in predicting successful symptom resolution. Patients who began treatment with a higher subjective perception of health showed a greater likelihood of clinical improvement, highlighting the psychological component as an integral part of treatment outcomes.

Conclusions

In summary, this study demonstrates that a holistic therapeutic approach significantly improves quality of life and clinical outcomes for SIBO patients and emphasizes the need for individualized treatments addressing nutrition, microbiota balance and symptom relief. Despite moderate normalization of diagnostic test results, significant clinical improvement highlights the importance of patient-reported outcomes. This is one of the first large-scale studies to specifically assess quality of life outcomes in SIBO patients using validated tools, making it a unique contribution to the field. These findings highlight the critical need for greater awareness and acceptance among health care providers of comprehensive SIBO management strategies. However, the authors also acknowledge important limitations, including the lack of a placebo or control group and the difficulty of isolating the effects of individual treatment components.

Future research should explore psychological interventions, long-term sustainability, and personalized diets to better address the profound impact of SIBO on patients' daily lives, ultimately improving standards of care and patient well-being worldwide.

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