The gut microbiota has the ability to modulate host energy homeostasis, which may regulate metabolic disorders. Functional oligosaccharide may positively regulate the intestinal microbiota. Therefore, effects of α-galactooligosaccharides (α-GOS) from chickpea on high-fat-diet (HFD)-induced metabolic syndrome and gut bacterial dysbiosis were investigated. After 6 weeks of intervention, HFD led to significant increases in levels of blood glucose, total cholesterol, triglyceride, glycated serum protein, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol of mice compared to normal-chow-fed mice. Meanwhile, all of the α-GOS-treated groups significantly decreased above parameters compared to the HFD group. HFD could significantly decrease the content of all bacteria, especially Bacteroides (9.82 ± 0.09 versus 10.3 ± 0.10; p < 0.05) and Lactobacillus (6.67 ± 0.18 versus 7.30 ± 0.24; p < 0.05), and a decrease in the production of short-chain fatty acids was also observed. Treatment with α-GOS significantly increased the number of Bifidobacterium (6.07 ± 0.23 of the low-dose treatment versus 5.65 ± 0.20 of the HFD group) and Lactobacillus (7.22 ± 0.16 of the low-dose treatment). It also significantly promoted the secretion of propionic and butyric acids. These results indicate that α-GOS from chickpeas may affect the metabolic disorders and gut bacterial ecosystem in a positive way.