The purpose of this study is to understand if chewing xylitol-gum initiated before 20 weeks of pregnancy and continued until delivery affects the bacteria that are found in the oral and vaginal cavities, signs of inflammation within the gingiva of the oral cavity, the health of the tissues in the mouth (clinical parameters of periodontal disease) and placentae, and the bacteria in the mouth and gut of newborns among pregnant individuals in Malawi. In addition, we will evaluate the impact of xylitol-containing chewing gum use during pregnancy on the offsprings neurodevelopment at approximately 6- and 18-months corrected age.

After consenting to the study, pregnant participants who have a singleton gestation and are <20 weeks' gestation will be randomised into either the intervention arm ( 6.36grams of daily xylitol; Epic dental gum, 1.06 grams Xylitol per piece of gum; chew two pieces for 5 minutes after meals, thrice a day) or the placebo control arm (Sorbitol Gum base; Epic sorbitol-containing gum, 0 grams/day of xylitol; chew two pieces for 5 minutes after meals, thrice a day) by randomly picking from a group of opaque, sealed envelopes containing group allocation. The participants will also undergo a dental assessment and sampling, and vaginal sampling at enrolment, 28- 30 weeks of pregnancy, at birth - 48 hours and 4-6 weeks after birth. In addition, placental and breastmilk specimens will be obtained at the time of delivery, and stored in a biobank for future analyses. The investigators will also obtain oral and meconium (and stool at 4-6 weeks) samples of their newborns at birth and 4-6 weeks after birth. Furthermore, at 6- and 18-months corrected age, the infants will undergo neurodevelopmental assessments using the the Hammersmith Infant Neurologic Exam (HINE), Developmental Assessment of Young Children 2nd Edition (DAY-C), and Malawi Development Assessment Tool (MDAT). The assessments will be done by two community health workers trained in these methods and will be compared to assessments by a paediatric neurologist.

Inclusion Criteria:

• Able to provide informed consent. For those under 18 years of age, consent will additionally be sought from the parent or guardian.
• A singleton at <20 weeks' gestation (based on ultrasound or best obstetric measurement)
• Planning to deliver at Area 25 health center.
• Willing to chew two pieces of gum thrice daily for 5 minutes after the morning, day and evening meals throughout pregnancy.
• Willing to undergo at least two dental exams including oral microbiota sampling at study enrolment <20 weeks of pregnancy, 28-30 weeks, at delivery/within 48 hours and 4-6 weeks after giving birth.
• Willing to have at least two vaginal sampling at study enrolment <20 weeks of pregnancy, 28-30 weeks, at delivery/within 48 hours and 4-6 weeks after giving birth.
• Able to speak Chichewa or English.
• Cognitively aware enough to be able to participate in the study.
• Willing to consent to all required aspects of protocol including allowing collection of placenta specimens, infant oral swab and meconium/stool sampling at birth/within 48 hours and 4-6 weeks after.

Exclusion Criteria:

• Those who upon screening and enrolment but dislike the taste of the gum and state they will not chew the gum throughout pregnancy.
• Gravidae with known or suspected non-viable pregnancy (including life threatening congenital anomalies such as cardiac, neurological or others).
• Pregnant individual has a life-threatening diagnosis such as cancer requiring treatment during pregnancy.
• Pregnant women with a known or suspected morbidly adherent placenta (such as placenta accrete, increta and percreta).

Data will be shared for investigators who have an IRB approved project and approach the researchers with a research plan that is approved by the study team.

1 year after the study conclusion will the data become available and be available for approximately 10 years after study completion.

Investigators interested in the study data should contact the Study PI (Dr. Ben Shayo - Benjamin.shayo@bcm.edu) or study team members (i.e. Dr. Greg Valentine - gcvalent@uw.edu).

Participants, data collectors (i.e. dental officers, study staff members, clinical officers), and data analysts will be blinded (triple-blinded) to group allocation throughout the study.