The microorganisms that form the gut microbiome begin colonizing the gut at birth. The microorganisms will establish a symbiotic relationship with the host when in a state of eubiosis. However, when there is an imbalance or lack of diversity in the microorganisms present in the gut microbiome, it will shift to a state of dysbiosis, which increases the risk of inflammatory bowel and neurodegenerative diseases. There are known factors that affect the infant intestinal microbiome: mode of delivery, gestational age, and exposures, such as the use of antibiotics and feeding methods. Studies have shown that maternal lifestyle, particularly stress levels and diet, has an association with the infant microbiome diversity. However, there is limited literature that examines how postpartum maternal sleep influences the intestinal microbiome diversity in infants. We hypothesized that sleep efficiency below 85%, total sleep time and nocturnal sleep time below 7 hours, and later nocturnal sleep onset would be associated with decreased gut microbiome diversity within the sample and between samples. 27 Mother-infant pairings were used for this sub-analysis. Postpartum maternal sleep data was obtained via actigraphs and sleep diaries while infant intestinal microbiome data was obtained through fecal samples swabbed from soiled diapers. Actigraphs recorded time, movement, temperature, and light for five 24-hour periods, and sleep diaries were used to supplement the actigraphy and ease the scoring of sleep. DNA samples were extracted and sequenced using next-generation sequences, and QIIME2 was used to analyze these sequences. Alpha- and beta-diversity results following sequencing revealed good postpartum maternal sleep efficiency is associated with increased infant gut microbiome diversity within and between samples. There was a trend for nocturnal sleep onset being associated with beta-diversity measurements which were driven by phylogenetic differences and abundance of bacteria. Nocturnal total sleep time and 24-hour total sleep time were not associated with alpha- and beta-diversity. Our findings as well as the scarcity of the literature illustrate the need for further investigations on the mechanics of maternal sleep efficiency association with infant gut microbiome. Future research is needed to further evaluate the trending nocturnal sleep onset influences on the infant gut microbiome beta-diversity with a larger and more diverse sample.