BARCELONA, Spain — Lower respiratory tract infections cause millions of deaths worldwide each year. While modern medicine remains focused on prescribing antimicrobial drugs to eliminate pathogens, experts argue that infection prevention through nonpharmacologic interventions such as nutrition and microbiome, pulmonary rehabilitation, and environmental exposure can reduce reliance on antibiotics — necessary to counter worsening antimicrobial resistance.

“Respiratory infection should not begin with antibiotics and end with microbiological cure,” said Sundeep Santosh Salvi, MD, PhD, director of the Pulmocare Research & Education (PURE) Foundation in Pune, India, at the European Respiratory Society (ERS) 2026 International Congress. “It should begin before infection by reducing susceptibility, continue during illness by strengthening host resilience, and extend beyond cure by restoring health and function.”

Nutrition and Rehabilitation

The host’s baseline physiologic state profoundly shapes susceptibility to infection and recovery. Gunar Günther, MD, pulmonologist at Inselspital Bern in Bern, Switzerland, and the University of Namibia in Windhoek, Namibia, presented historical data from Denmark (1876-2022) showing an 80% drop in mortality and transmission driven entirely by nonpharmacologic public health measures, including improved housing, better hygiene, and diet. “Nutrition is extremely important,” he said.

The RATIONS trial, a cluster-randomized controlled trial (RCT) conducted across India, enrolled 2800 patients with active tuberculosis (TB) and 10,300 of their household contacts to assess the therapeutic and preventive value of structured nutritional support.

For patients with active disease, providing a daily nutritional supplement of 1200 kcal and 52 grams of protein reduced overall mortality by 61%, and patients gained at least 5% of their weight within the first 2 months. Providing household contacts daily food packages containing 750 kcal, 23 grams of protein, and essential micronutrients reduced overall TB incidence by 39% and lowered the incidence of microbiologically confirmed TB cases by 48%.

These findings informed the updated 2026 WHO Consolidated Guidelines on Tuberculosis: Module 6: Tuberculosis and Comorbidities. The World Health Organization now strongly recommends routine nutritional assessment, counseling, and targeted interventions for all patients with active TB as part of standard care. 

Günther also spoke about the growing role of pulmonary rehabilitation across acute and chronic respiratory infections.

In non-ICU patients hospitalized with community-acquired pneumonia (CAP), early physical therapy and mobility interventions provide measurable clinical benefits. A systematic review of nine RCTs demonstrated that inpatient physiotherapy, comprising tailored exercise, early ambulation, and conventional chest physical therapy, significantly reduces hospital length of stay and relieves acute dyspnea compared with standard care alone.

However, evidence across broader inpatient populations remains mixed. A 2022 review of eight RCTs found that while specialized chest physiotherapy slightly shortens hospital stay, fever duration, ICU days, and mechanical ventilation time, the overall certainty of the evidence remains low to very low. Consequently, routine physical therapy has yet to be formally incorporated into major CAP clinical practice guidelines.

In contrast to CAP, the evidence supporting pulmonary rehabilitation in post-TB lung disease is increasingly robust. A 2025 meta-analysis, along with recent RCTs in Uganda and Kyrgyzstan, demonstrated that a 6-week post-TB pulmonary rehabilitation program yields profound functional gains compared with standard care. Participants could walk for longer and improved their quality of life.

“Pulmonary rehabilitation shows a clear short-term effect in restoring exercise capacity and quality of life after tuberculosis,” Günther said. However, he said that questions remain regarding the optimal timing of intervention, the long-term sustainability of functional gains, and overall cost-effectiveness.

The Microbiome: Gut and Lung Axis

Emerging research into the gut-lung axis reveals that the intestinal microbiome plays an active, remote-regulatory role in pulmonary immune defenses. Rather than acting as isolated ecosystems, the gut and lungs maintain continuous crosstalk, in which bacterial metabolites, such as short-chain fatty acids, modulate systemic inflammation and innate immune responses during respiratory infections.

In CAP, specific gut bacteria appear to exert a protective effect against pulmonary pathogens. Preclinical models demonstrate that pre-treatment with Faecalibacterium prausnitzii, an abundant, butyrate-producing gut bacterium, or butyrate administration significantly reduces bacterial proliferation, systemic dissemination, and tissue inflammation following Klebsiella pneumoniae infection.

Clinical observation shows that gut levels of F prausnitzii are markedly depleted in hospitalized patients with CAP compared with healthy control groups. Higher baseline intestinal abundance of F prausnitzii strongly correlates with faster clinical recovery and higher rates of successful discharge.

Targeted probiotic interventions have also shown promise in early clinical trials. In an RCT involving 80 young, noncomorbid patients with CAP, supplementing standard antibiotic therapy with a dual-strain probiotic (Bacillus subtilis and Streptococcus faecium) led to a significantly shorter duration of fever, improved general clinical condition, and lower C-reactive protein levels at 2 weeks compared with antibiotics alone. A 2022 review of 24 studies further noted that general probiotic use reduced the incidence of upper respiratory tract infections by 18% and shortened average symptom duration by 1.2 days.

Standard multidrug anti-TB regimens cause profound, long-lasting gut dysbiosis that persists for months after treatment completion. Microbiome support can mitigate treatment side effects. An RCT of 429 patients demonstrated that coadministering Lactobacillus casei significantly reduced drug-induced liver injury. Patients receiving L casei exhibited lower bilirubin and alkaline phosphatase levels, along with reduced pro-inflammatory cytokine levels.

However, despite these hepatoprotective effects, no RCTs to date have demonstrated that prebiotics or probiotics improve core clinical endpoints such as culture conversion rates, treatment recurrence, or long-term post-TB lung outcomes.

“Microbiome modulation is a rapidly growing area with strong biological rationale,” he said. “But high-quality trial evidence for hard clinical endpoints in CAP and TB remains limited.”

Environmental and Behavioral Interventions

Household air pollution, from burning solid biomass fuels, such as wood, coal, dung, and kerosene, causes over 3.2 million premature deaths annually, disproportionately affecting women and young children. Ambient and indoor pollutants, including fine particulate matter, nitrogen dioxide, sulfur dioxide, ground-level ozone, and carbon monoxide, impair local lung defense mechanisms and increase the risk for infection. 

At the cellular level, exposure to combustion byproducts leads to the accumulation of heavy carbon particles within alveolar macrophages. Induced sputum analysis reveals significantly higher carbon loading in the macrophages of individuals living in high-biomass environments compared with those residing in low-pollution areas.

This physical particulate loading impairs core phagocytic mechanisms. Ex vivo studies confirm that exposing human and murine alveolar macrophages to concentrated ambient particles alters cells’ ability to ingest and destroy bacteria. The underlying mechanism driving this phagocytic failure is metabolic disruption. Peripheral blood monocyte-derived macrophages from people exposed to biomass or tobacco smoke, both with and without clinical chronic obstructive pulmonary disease, demonstrate severe, widespread phagocytic defects against respiratory pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Pseudomonas aeruginosa.

Immuno-metabolic analysis reveals that smoke-exposed macrophages suffer from compromised glucose and free fatty acid utilization. Deprived of essential metabolic energy, these immune cells lose the cellular fuel required to engulf and digest microbes.

The widespread adoption of nonpharmaceutical interventions during the COVID pandemic demonstrated that behavioral and structural measures, including consistent face mask use in high-risk settings, can reduce the incidence of lower respiratory tract infections. Population-level data published in The Lancet Infectious Diseases revealed that pandemic-era behavioral changes reduced the global incidence of influenza and respiratory syncytial virus by approximately 60% and prevented an estimated 25 million episodes of non-COVID lower respiratory tract infection worldwide. Overall, behavioral modifications reduced the risk for respiratory infection by more than 50%.

Also, regular physical activity, proper hydration, and good sleep hygiene enhance systemic immune surveillance, accelerate pathogen clearance, and lower peak viral loads during acute respiratory infections.

Günther and Salvi reported having no relevant financial relationships.

Manuela Callari is a freelance science journalist specializing in human and planetary health. Her work has been published in The Medical Republic, Rare Disease Advisor, New Scientist, The Guardian, MIT Technology Review, and others.