Antibiotics are usually prescribed to cure infections but they also have significant modulatory effects on the gut microbiota. Several alterations of the intestinal bacterial community have been reported during antibiotic treatment, including the reduction of beneficial bacteria as well as of microbial alpha-diversity. Although after the discontinuation of antibiotic therapies it has been observed a trend towards the restoration of the original condition, the new steady state is different from the previous one, as if antibiotics induced some kind of irreversible perturbation of the gut microbial community. The poorly absorbed antibiotic rifaximin seem to be different from the other antibiotics, because it exerts non-traditional effects additional to the bactericidal/bacteriostatic activity on the gut microbiota. Rifaximin is able to reduce bacterial virulence and translocation, has anti-inflammatory properties and has been demonstrated to positively modulate the gut microbial composition. Animal models, culture studies and metagenomic analyses have demonstrated an increase in Bifidobacterium, Faecalibacterium prausnitzii and Lactobacillus abundance after rifaximin treatment, probably consequent to the induction of bacterial resistance, with no major change in the overall gut microbiota composition. Antibiotics are therefore modulators of the symbiotic relationship between the host and the gut microbiota. Specific antibiotics, such as rifaximin, can also induce eubiotic changes in the intestinal ecosystem; this additional property may represent a therapeutic advantage in specific clinical settings.

Fusobacterium nucleatum, a gram-negative anaerobic bacterium, has emerged as a significant player in colorectal cancer (CRC) pathogenesis. The bacterium causes a persistent inflammatory reaction in the colorectal mucosa by stimulating the release of pro-inflammatory cytokines like IL-1β, IL-6, and TNF-α, creating an environment conducive to cancer progression. F. nucleatum binds to and penetrates epithelial cells through adhesins such as FadA, impairing cell junctions and encouraging epithelial-to-mesenchymal transition (EMT), which is associated with cancer advancement. Additionally, the bacterium modulates the host immune system, suppressing immune cell activity and creating conditions favorable for tumor growth. Its interactions with the gut microbiome contribute to dysbiosis, further influencing carcinogenic pathways. Evidence indicates that F. nucleatum can inflict DNA damage either directly via reactive oxygen species or indirectly by creating a pro-inflammatory environment. Additionally, it triggers oncogenic pathways, especially the Wnt/β-catenin signaling pathway, which promotes tumor cell growth and longevity. Moreover, F. nucleatum alters the tumor microenvironment, impacting cancer cell behavior, metastasis, and therapeutic responses. The purpose of this review is to elucidate the molecular mechanisms by which F. nucleatum contributes to CRC. Understanding these mechanisms is crucial for the development of targeted therapies and diagnostic strategies for CRC associated with F. nucleatum.

Shear-wave elastography is an accurate and reproducible noninvasive technique for efficiently detecting significant liver fibrosis and, less accurately, mild liver fibrosis in children with nonalcoholic steatohepatitis. PurposeTo evaluate the diagnostic accuracy of shear-wave elastography (SWE) in identifying different degrees of fibrosis in a cohort of consecutive children and adolescents with nonalcoholic steatohepatitis (NASH).Materials and MethodsConsecutive pediatric patients scheduled to undergo liver biopsy were studied with an ultrasonography-based SWE system. Elastography was performed in 68 of 69 patients with biopsy-proved NASH (37 boys and 31 girls; mean age, 12.6 years ± 2.48; age range, 8–17 years). The correlations among laboratory findings, liver stiffness, and fibrosis score were analyzed, and the area under the receiver operating characteristic curve (AUC) was used to assess the presence of any fibrosis (score ≥F1) or significant fibrosis (score ≥F2). Findings from histologic examination were used as the standard of reference.ResultsSWE showed a very high correlation with liver fibrosis (P < .001) at univariate and multivariate analyses. The AUCs for the association of any and significant fibrosis were ...