Introduction: Diet plays a crucial role in shaping the human gut microbiota (GM), but studies investigating the effects of dietary patterns on the GM are still limited. Objective: This study aimed to review the effects of different dietary patterns on the human GM. Methods: This review included observational and clinical studies published in PubMed/MEDLINE between 2019 and 2023. Results: Initially, 1,148 articles were identified and 12 articles were included. Studies were conducted in various countries, predominantly in the USA (n=3), and most evaluated the effects of the Mediterranean diet (n=3) and vegetarian/vegan diet (n=3). No included study evaluated the DASH (Dietary Approaches to Stop Hypertension) diet. The Western diet showed negative effects on the GM, characterized by an increase in Firmicutes bacteria and a reduction in bacterial diversity and richness. These effects are associated with cardiovascular and inflammatory diseases. The low carb diet showed conflicting results among studies. The ketogenic diet appears to be associated with a decrease in the Firmicutes/Bacteroidetes ratio, especially when whey protein or plant proteins are the main protein sources in the diet. Mediterranean and vegetarian/vegan diets had beneficial effects on the GM, mainly associated with high fiber intake from fruits, vegetables, and legumes, leading to a reduction in the Firmicutes/Bacteroidetes ratio, an increase in Akkermansia bacteria, and higher production of short-chain fatty acids (SCFAs). Conclusion: Dietary pattern exerts distinct effects on the GM, influencing bacterial richness and diversity differently. Further studies are recommended in this area, including investigation of the DASH diet’s impact on the GM. Keywords: Gastrointestinal microbiome; dietary patterns.