Microbiota-derived molecules called short-chain fatty acids (SCFAs) play a key role in the maintenance of the intestinal barrier and regulation of immune response during infectious conditions. Recent reports indicate that SARS-CoV-2 infection changes microbiota and SCFAs production. However, the relevance of this effect is unknown. In this study, we used human intestinal biopsies and intestinal epithelial cells to investigate the impact of SCFAs in the infection by SARS-CoV-2. SCFAs did not change the entry or replication of SARS-CoV-2 in intestinal cells. These metabolites had no effect on intestinal cells’ permeability and presented only minor effects on the production of anti-viral and inflammatory mediators. Together our findings indicate that the changes in microbiota composition of patients with COVID-19 and, particularly, of SCFAs do not interfere with the SARS-CoV-2 infection in the intestine.

BACKGROUND: The increase in the incidence and prevalence rates of inflammatory bowel disease (IBD) is evident in many newly industrialized countries in Asia, Africa, Eastern Europe, and the American continent. In Brazil, records are still scarce, and further studies on this topic are needed. OBJECTIVE: To evaluate the epidemiological profile and clinical characteristics of patients with IBD who were followed up at a reference service in the state of São Paulo. METHODS: We retrospectively analyzed the medical records of patients with IBD who were followed up in a Brazilian Referral Center. RESULTS: A total of 625 patients was evaluated, 416 with Crohn’s disease (CD), 190 with ulcerative colitis (UC), and 19 with indeterminate colitis. The average age of the patients was 31.6 years, with a homogeneous distribution between males and females patients. In patients with CD, the most predominant Montreal classification was A2, L3, and B1, with 44.8% of patients presenting with perianal disease; in UC, it was E2, and S0. The main extraintestinal manifestation was rheumatologic, followed by cutaneous and ophthalmic lesions. The majority of patients (85.4%) used some type of medication, the most frequent being aminosalicylates in patients with UC and biological therapy in patients with CD. Regarding surgeries, in CD, a significant percentage of patients underwent some type of surgical procedure, unlike the UC patients, including fistulotomies and placement of seton, derivative ostomies, enterectomy, ileocecectomy/right colectomy, total or partial colectomy, and strictureplasty. Only 195 (31.2%) patients lived in the city of Campinas, while 443 (70.9%) were from the 7th Regional Health Department (RHD), which corresponds to the macro-region of Campinas. CONCLUSION: In this study, most patients came from the 7th RHD of Campinas; the patients were young, with no predominance of either sex; there was a higher frequency of patients with CD (66.6%). Most of them (85.4%) were undergoing pharmacological treatment, and a significant percentage of CD patients had undergone surgery.

Infections caused by fungi are prominent in our environment and can be potentially fatal. paracoccidioidomycosis (PCM), caused by fungi of the Paracoccidioides genus, is the most frequent systemic mycosis in Brazil and the main cause of death among immunocompetent individuals. The antifungal therapy for PCM is usually effective but side effects and relapses are often reported. The latter could be avoided with alternative or complementary therapies aimed at boosting the immune response to combat this pathogen. Recent reports have pointed at the importance of an effective cellular immune response, with the participation of Th1 cells, in the resistance to and control of Paracoccidioides infection. The ArtinM lectin, extracted from jackfruit (Artocarpus heterophyllus) seeds, exhibits immunomodulatory activity against several intracellular pathogens, including Paracoccidioides brasiliensis, by promoting the development of a Th1 immune response. The aim of this work was to characterize the effect of ArtinM on peripheral blood cells of patients with PCM and on those of control individuals infected with fungal yeasts cells in vitro. Our results demonstrate that ArtinM activates human neutrophils in vitro, leading to an increase in cytokine production and CD54 expression. ArtinM activated P. brasiliensis-infected neutrophils from both healthy individuals and patients with PCM. This activation was not dependent on the dectin-1 receptor, because pre-incubation with laminarin, a dectin-1 receptor blocker, did not reverse the activated state of the cells. ArtinM also stimulated human peripheral blood mononuclear cells to secrete pro-inflammatory Th1-related cytokines, which are protective against Paracoccidioides infection. These data support the immunostimulatory action of ArtinM and encourage new studies using the lectin for the immunotherapy of PCM.

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