Background: Impaired gut barrier function has been reported in some functional gastrointestinal (GI) disorders. Evidences suggest that gut microbiota affects GI motility in particular Lactobacillus species elicits anti-inflammatory activity and exerts protective effects on damage induced by pathogen Gram negative-derived lipopolysaccharide (LPS). LPS produced an oxidative imbalance in human colonic smooth muscle cells (SMC) that persists after LPS-washout and contributes to SMC morphofunctional alterations. The aim was to evaluate if supernatants harvested from LGG cultures protect SMC from LPS-induced myogenic damage. Methods: L. rhamnosus GG (ATCC 53103 strain) was grown in MRS medium and samples were collected from bacterial cultures in middle exponential phase, in early, in middle and late stationary phase (overnight). Supernatants were recovered, filtered and stored at -20 8C. Highly pure human SMC culture was then exposed for 24 h to highly purified LPS (1 mg/ml) of E. coli (O111:B4) in the absence and presence of the supernatants. Their effects were evaluated on LPS-induced SMC morphofunctional alterations and pro-inflammatory IL-6 production. Data are expressed as mean AE SE (P < 0.05 significant). Results: LPS induced persistent significant 20.7% AE 1.2 cell shortening and 35.2% AE 2.6 decrease in contraction of human colonic SMC. These alterations were paralleled to a 238.5% AE 82.5% increase in IL-6 production. These effects disappeared in the presence of LGG-supernatants, following a progression related to LGG growth curve phases. Supernatants collected in the middle exponential phase already significantly partially restored LPS-induced cell shortening by 43.4% AE 10.2% and IL-6 increase by 47.6% AE 13.1%, but had no effect on LPS-induced inhibition of contraction. Supernatants collected later, in the early and middle stationary phase, further counteract LPS-induced damage, including inhibition of contraction. Maximal protective effects were observed with supernatants of the late stationary phase where LPS-induced cell shortening was reversed by 86% AE 4.7%, inhibition of contraction by 98.2% AE 1.8%, and IL-6 basal production by 91.3% AE 0.6%. Conclusions: LGG-secreted products are substances/byproducts able to directly protect human SMC from LPS-induced myogenic damage. Novel insights are then provided about the possibility that LGG-derived products could reduce the risk of progression to a post-infective motor disorder.

Background: The Fatigue Rate Index (FRI) is a parameter in anorectal manometry (ARM) to assess sustained voluntary contraction, considering the squeeze pressure and fatigability of the external anal sphincter. It is used in adults to detect fecal incontinence even in patients who present normal squeeze pressures. The FRI in adult patients with functional constipation is similar to controls. Objective: The aim of this study was to evaluate the feasibility and values of FRI in children in relation to the values previously established in adults and comparing children with functional constipation and retentive fecal incontinence to children without retentive fecal incontinence. Methods: This retrospective study evaluated 105 ARM performed from Jan 2014 to Apr 2015. 42 patients were selected (were able to perform a voluntary contraction and had no co-morbidities other than functional constipation). 14 (33.3%) of those collaborated in sustaining contraction for 40 seconds (s), allowing the evaluation of the FRI. Patients with retentive fecal incontinence secondary to functional constipation (n=7, aged 6 to 13 years, six boys) were our interest group. Patients with functional constipation without fecal incontinence (n=7, aged 6 to 13 years, four boys) were considered a reference group. The ARM were performed with a radial eight-channel perfusion catheter (DynamedTM, São Paulo, Brazil) and the FRI was calculated (Proctomaster 6.4) in the first 20 s and overall 40 s of sustained voluntary contraction. Results: 14 of the selected 42 collaborated in sustaining contraction for 40 s, allowing the evaluation of the FRI. In the first 20 s of contraction, the fecal incontinence group showed a significantly higher mean FRI (2.48±1.39 min) compared to the reference group (1.13±0.72 min, P=0.042), which was not observed in the 40 s interval due to less uniform contraction. The anal resting pressure was higher in the fecal incontinence group (76.83 mmHg) than in the reference group (54.13 mmHg), but the statistical study did not reach significance (P=0.051). Conclusion: The FRI is feasible in children. The mean FRI obtained in this study is lower than the reported in constipated adults. The mean FRI among children with functional constipation and retentive fecal incontinence is higher than among constipated children without retentive fecal incontinence.