Last update and review: December 18, 2020.
Recent findings on methanogens and the use of probiotics in SIBO reflect our experience.
In a recent study, Achufusi et al., 2020 (1), the authors did a review of small intestinal bacterial overgrowth (SIBO). In the paper, there is a summary of the recent findings on methanogens and the use of probiotics in SIBO. The results reported by Achufusi et al., 2020 (1), reflect our own observations in our consulting practice. Indeed, probiotics do not usually improve symptoms, and often worsen them, in persons with a suspect overgrowth of methanogens. Here is the relevant passage from Achufusi et al., 2020 (1), in this article:
In contrast, a recent study has also shown that probiotics may provoke symptoms among SIBO patients including gas, bloating, and brain fogginess [31]. In the study, probiotic cessation, and a course of antibiotics, resolved brain fogginess while improving other gastrointestinal symptoms (p = 0.005) in 23/30 subjects (77%). This suggests that not all probiotics are of equal efficacy and should be used with caution in patients with SIBO. A 2018 study aimed at assessing how recent probiotic use effects breath testing yielded interesting results that have some questioning the role of probiotics in SIBO management (Mitten E, Goldin A: S660: Recent probiotic use is independently associated with methane-positive breath test for small intestinal bacterial overgrowth. The study showed that probiotic use within one month was independently associated with increased methane positive LBT in patients presenting with suspected SIBO symptoms. Probiotic users were significantly more likely to have positive LBT compared to non-users (93.6% vs 65.7%, p = 0.003). More specifically, those individuals with recent probiotic use were more likely to have methane-positive LBT but not hydrogen-positive LBT. These findings suggest that probiotic use can predispose to overgrowth of methanogenic bacteria. The use of probiotics can potentially increase the risk for methane predominant variant of SIBO which has been associated with constipation-predominant symptoms. The lack of clear consensus regarding probiotic use suggests that additional large scale studies are needed to better understand the effects of probiotics on SIBO risk.
We do not recommend breath tests in our consulting practice.
The rest of the article is rather mediocre, since nothing interesting in terms of treatment is mentioned. We, however, put below a couple of slides from the study by Achufusi et al., 2020 (1). One of them describes the preparation to a breath test. We do not recommend breath tests in our consulting practice. Symptoms described by our consulting clients are informative enough.
More creative approaches are needed to use probiotics successfully in SIBO and IBS with signs of methanogens overgrowth.
We should not stop exploring the use of probiotics based on the setbacks described above. Probiotics play other important roles, one of them is balancing our immune system. We continue our experiments with different protocols and different probiotics in our consulting practice.
Selected references:
1. Achufusi et al. Cureus. 2020 Jun 27;12(6):e8860.