Tropical Infections and the Gut Microbiome: Dysbiosis, Recovery, and Clinical Implications

Biruk Demisse Ayalew¹Muhammad Umar²Muhammad Saeed³Ahtisham Ali⁴Kaleb Assefa Berhane⁵Temesgen Mamo Sharew⁵Yonatan Abbawa Zewdie⁶Eskeatnaf Yosef Getachew⁵Zemichael Getu Alemayehu⁶Abate Bane Shewaye^7*

• ¹Department Internal Medicine, School of Medicine, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia
• ²Khairpur Medical College, Khairpur mir's, Pakistan
• ³D. G. Khan Medical College, Dera Ghazi Khan, Pakistan
• ⁴Riphah International University, Islamabad, Ethiopia
• ⁵School of Medicine, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia
• ⁶College of Health Science, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
• ⁷Department Internal Medicine, College of Health Science, School of Medicine, Addis Ababa University,, Addis Ababa, Ethiopia

The gastrointestinal (GI) microbiome, crucial for host health through its roles in digestion, immunity, and pathogen protection, is significantly disrupted by tropical infections. This disruption, termed dysbiosis, manifests as a loss of beneficial microbes, an increase in harmful bacteria, and altered microbial composition. This review synthesizes recent evidence (2019-2025) on how these infections impact the gut microbiome, influence host recovery, and contribute to long-term health outcomes. A structured literature search was conducted across PubMed, Scopus, and Web of Science, focusing on human GI microbiome dynamics, dysbiosis patterns, and recovery mechanisms in the context of tropical infectious diseases. Findings indicate that common tropical infections, such as cholera, giardiasis, and ascariasis, consistently lead to dysbiosis, characterized by decreased microbial diversity, an increase in opportunistic pathogens like Proteobacteria, and impaired gut barrier function. While natural host processes contribute to recovery, this is significantly influenced by host immunological status, infection severity, and environmental factors. Therapeutic interventions, including probiotics and fecal microbiota transplantation (FMT), show promise in aiding microbiome restoration. Understanding these intricate interactions is crucial for developing effective strategies to manage and treat the associated long-term consequences, including post-infectious GI disorders and malnutrition, particularly in vulnerable populations.