Exhaled breath analysis is emerging as a non-invasive tool for health monitoring, with methane (CH₄) serving as a key biomarker for gut health. Elevated methane levels in breath are associated with gastrointestinal disorders such as irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO). While traditional gas chromatography methods provide accurate measurements, their complexity and cost limit real-time, point-of-care applications. Recent advancements in sensor technologies, including nano material-based sensors and AI-enhanced detection methods, have significantly improved sensitivity and specificity in methane detection. Optical methods, such as photo acoustic spectroscopy (PAS) and super continuum laser absorption spectroscopy (SC-LAS), enable real-time multi-gas detection with minimal cross-interference. Meanwhile, metal oxide semiconductor (MOS) sensors provide compact and cost-effective solutions, though challenges remain in stability and selectivity. This review integrates recent studies and highlights a comparative analysis of various sensor technologies, focusing on selection criteria, performance metrics, and environmental considerations. The development of portable and highly selective breath sensors will be critical for advancing methane-based gut health diagnostics. Additionally, advancements in deep learning and convolution neural networks (CNNs) have been explored for enhancing the precision of methane level estimation and real-time breath analysis.