How does fatty liver affect pneumonia outcomes?

Roughly one in three adults in Europe has a fatty liver, and most of them do not know it.

Fatty liver is closely linked to obesity, diabetes and insulin resistance, in other words to metabolic health. For a long time it was seen only as a liver disease, but there is growing evidence that it changes how the whole body defends itself against infection.

Pneumonia is one of the most common reasons for hospital and intensive care admission. Our earlier studies showed that patients with fatty liver more often have a severe course of disease, but we do not yet know why.

In SteatoCAP we will follow more than 350 patients with pneumonia. A simple, painless ultrasound scan will show whether they have a fatty liver, and we will then track their immune response and gut bacteria. Artificial intelligence will help us find patterns in these data that the human eye cannot see, so that doctors can identify high-risk patients earlier.

A prospective study of MASLD, the immune response and pneumonia outcomes.

Our team’s previous studies linked steatotic liver disease with adverse outcomes of sepsis and pneumonia. SteatoCAP extends this work by longitudinally integrating clinical, immunological and microbiome data.

Proposed mechanisms include an altered hepatic acute-phase response, neutrophil dysfunction driven by insulin resistance, and reduced clearance of bacterial products due to impaired sinusoidal microcirculation. The framework is the gut–liver–lung axis: gut dysbiosis and increased intestinal permeability may disturb immune balance and contribute to a dysregulated pulmonary response.

A prospective observational cohort (n > 350) with transient elastography (CAP, LSM) within 48 h of admission; a randomly selected nested subcohort (n = 120) with longitudinal cytokine profiling, T-cell phenotyping and 16S rRNA (V3–V4) sequencing of the stool microbiota; a biobank for future multi-omics analyses; and data integration with machine-learning methods. The primary outcome is a composite of advanced respiratory support, ICU admission and mortality.

Sources: Ebrahimi et al., Clin Gastroenterol Hepatol 2023; Gjurašin et al., Life (Basel) 2022; Krznarić et al., J Clin Med 2024.