Abstract: A low-oxygen system is directed to culturing a diverse microbiome and includes an anaerobic chamber and at least one microfluidic device removably inserted in the anaerobic chamber. The microfluidic device includes a first microchannel in which a first level of oxygen is maintained, and a second microchannel in which a second level of oxygen is maintained, the second level of oxygen having a greater oxygen concentration than the first level of oxygen. The microfluidic device further includes a membrane located at an interface region between the first microchannel and the second microchannel, the membrane further having a plurality of pores via which oxygen flows from the second microchannel to the first microchannel to form an oxygen gradient in the first microchannel. The system further includes a culture system provided in the first microchannel and including oxygen-sensitive anaerobic bacteria.