The effect of salivary flow rate on the risk of bad breath (halitosis) during the Ramadan fasting

Background: Ramadan fasting is a significant religious practice for Muslims, characterized by abstinence from food and drink from dawn to sunset. This fasting routine induces physiological changes, including reduced salivary flow and altered salivary composition, which may compromise oral health. These changes increase the risk of halitosis and other oral issues due to decreased protective functions of saliva and the proliferation of volatile sulfur compound (VSC)-producing bacteria. Objective: To review the relationship between reduced salivary flow during Ramadan fasting and the risk of halitosis, as well as to identify effective preventive measures to mitigate these effects. Method: A literature review was conducted using secondary data from databases such as PubMed, ScienceDirect, and Google Scholar. The inclusion criteria focused on studies published between 2017 and 2025 that explored salivary flow rate, halitosis, and the effects of Ramadan fasting. Results: The review highlighted a significant reduction in salivary flow, with rates decreasing up to 50% during fasting. This reduction leads to an increase in VSC levels, which are the primary contributors to halitosis. Additionally, fasting affects the composition of saliva, including lower levels of phosphate and calcium, further exacerbating oral health issues. Conclusion: Ramadan fasting significantly influences oral cavity health by reducing salivary flow and altering its composition, increasing the risk of halitosis and other dental issues. Halitosis is primarily caused by volatile sulfur compounds produced by gram-negative anaerobic bacteria thriving in reduced saliva conditions.