In recent years, the gut microbiota has been considered as a full-fledged actor of the gut–brain axis, making it possible to take a new step in understanding the pathophysiology of both neurological and psychiatric diseases. However, most of the studies have been devoted to gut bacterial microbiota, forgetting the non-negligible fungal flora. In this review, we expose how the role of the fungal component in the microbiota-gut-brain axis is legitimate, through its interactions with both the host, especially with the immune system, and the gut bacteria. We also discuss published data that already attest to a role of the mycobiome in the microbiota-gut-brain axis, and the impact of fungi on clinical and therapeutic research.

Cystic fibrosis (CF) is a systemic genetic disease that leads to pulmonary and digestive disorders. In the majority of CF patients, the intestine is the site of chronic inflammation and microbiota disturbances. The link between gut inflammation and microbiota dysbiosis is still poorly understood. The main objective of this study was to assess gut microbiota composition in CF children depending on their intestinal inflammation. We collected fecal samples from 20 children with CF. Fecal calprotectin levels were measured and fecal microbiota was analyzed by 16S rRNA sequencing. We observed intestinal inflammation was associated with microbiota disturbances characterized mainly by increased abundances of Staphylococcus, Streptococcus, and Veillonella dispar, along with decreased abundances of Bacteroides, Bifidobacterium adolescentis, and Faecalibacterium prausnitzii. Those changes exhibited similarities with that of Crohn’s disease (CD), as evidenced by the elevated CD Microbial-Dysbiosis index that we applied for the first time in CF. Furthermore, the significant over-representation of Streptococcus in children with intestinal inflammation appears to be specific to CF and raises the issue of gut–lung axis involvement. Taken together, our results provide new arguments to link gut microbiota and intestinal inflammation in CF and suggest the key role of the gut–lung axis in the CF evolution.

Background Congenital esophageal stenosis (CES) is a rare condition frequently associated with esophageal atresia (EA). There are limited data from small series about the presentation, treatment, and outcomes of CES. Methods Medical records of all patients with CES included in the French Network on Esophageal Malformations and Congenital Diseases were reviewed retrospectively with regard to diagnosis, treatment, and outcome. Results Over 18 years, 61 patients (30 boys) had CES, and 29 (47%) of these patients also had EA. The mean age at diagnosis was 24 months (1 day to 14 years) and was younger in patients with CES and EA than in those with isolated CES (7 vs. 126 months, p < 0.05). Twenty-one of the 61 patients with CES had no clinical symptoms: in three patients, the findings were incidental, and in 18 of the 29 patients with associated EA, CES was diagnosed at the time of surgical repair of EA or during a postoperative systematic esophageal barium study. In the 40 other patients, at diagnosis, 50% presented with dysphasia, 40% with vomiting, 50% with food impaction, and 42% with respiratory symptoms. Diagnosis of CES was confirmed by esophageal barium study (56/61) and/or esophageal endoscopy (50/61). Sixteen patients had tracheobronchial remnants (TBR), 40 had fibromuscular stenosis (FMS), and five had membrane stenosis (MS). Thirty-four patients (56%) were treated by dilation only (13/34 remained asymptomatic at follow-up); 15 patients were treated by dilation but required later surgery because of failure (4/15 remained asymptomatic at follow-up); and nine patients had a primary surgical intervention (4/9 were asymptomatic at follow-up). Dilation was complicated by esophageal perforation in two patients (3.4%). At follow-up, dysphagia remained in 36% (21/58) of patients, but the incidence did not differ between the EA and the isolated CS groups (10/29 vs. 7/32, p = 0.27). Conclusions CS diagnosis can be delayed when associated with EA. Dilation may be effective for treating patients with FMS and MS, but surgical repair is often required for those with TBR. Our results show clearly that, regardless of the therapeutic option, dysphagia occurs frequently, and patients with CES should be followed over the long term.

Infliximab, a monoclonal antibody against tumor necrosis factor-alpha, has been shown to be effective for the treatment of refractory Crohn’s disease in adult patients, but experience in pediatrics is limited. This retrospective study included 88 children and adolescents, 39 girls and 49 boys, with a median age of 14 years (range 3.3–17.9). Infliximab was indicated for active disease (66%) and/or fistulas (42%) that were refractory to corticosteroids (70%), and/or other immunosuppressive (82%) agents, and/or parenteral nutrition (20%). Patients received 1 to 17 infusions (median 4) of 5 mg/kg (range 3.8–7.3) of infliximab during a median time period of 4 months (1–17 months). Infusion reaction was noted in 13 patients (15%), with a total of 16 reactions in 450 infusions (4%). At Day 90 after the first infusion of infliximab, symptoms improved in 49% of patients, whereas 29% of patients were in remission and 13% of patients relapsed. From Day 0 to Day 90, Harvey–Bradshaw score decreased from 7.5 to 2.8 (P < 0.001), C-reactive protein from 36 to 16 mg/L (P < 0.01), and 1-hour erythrocyte sedimentation rate from 35 to 17 mm (P < 0.01). Dosage of corticosteroids decreased from to 0.59 to 0.17 mg/kg/d (P < 0.001); 53% of patients could be weaned of corticosteroids and 92% of parenteral nutrition. Treatment with infliximab is well tolerated and effective in most children and adolescents with Crohn’s disease that is refractory to conventional immunosuppressive therapy. Nevertheless, long-term efficacy remains to be shown, and further studies are urgently needed to precisely determine the best modality of continuing treatment.