Low FODMAPs diet (LFD) is a common restrictive diet to manage irritable bowel syndrome (IBS) symptoms. However, there is no consensus on alleviating the effects of this diet. The umbrella systematic review with meta-analysis was conducted to investigate the effect of LFD on IBS symptoms and secondary outcomes of patients, which was not reported in the previous meta-analyses. We performed a systematic literature search in PubMed, Scopus, and ISI Web of Science up to December 2023. The methodological quality of the systematic reviews and their included trials was evaluated by AMSTAR2 and the Cochrane risk‐of‐bias, respectively. Rating the certainty of evidence tool was carried out by the GRADE approach. The data about IBS symptoms, quality of life (QoL), microbiome diversity, and stool short-chain fatty acids were extracted. A random-effects (if RCTs ≥ 6) or a fixed-effects model (if RCTs < 5) was used to recalculate the effect sizes and 95%CIs and report in both qualitative and quantitative terms (pooled risk ratio, Hedges' g, and weighted mean difference). A total of 658 articles were initially identified, 11 meta-analyses and 24 RCTs reporting 28 outcomes with 1646 participants included. The LFD can significantly affect the clinical improvement of total symptoms, according to the IBS-SSS questionnaire (RR: 1.42, 95% CI: 1.02, 1.97, P= 0.04) in all subtypes of IBS, and also, were favorable effects on stool consistency (WMD: -0.48, 95% CI: -0.902, -0.07) and frequency (WMD: -0.36, 95% CI: -0.61, -0.10), and some other GI symptoms in both less and more than 4 weeks of diet intervention except stool consistency which needs more than 4 weeks of LFD implementation. A significant QoL improvement was observed, but not in the anxiety and depression state. Also, some studies showed that LFD might have increased the fecal pH and dysbiosis and reduced SCFA and the abundance of Bifidobacterium. In conclusion, LFD can alleviate symptoms and QoL in IBS patients, although dysbiosis may occur. Considering the low certainty of evidence, strong RCTs with more appropriate designs are needed.