Obesity is caused by several factors. Gut microbiota composition is known to be one of the factors to play a role in modulating the obesity process. Nutrient factors and bioactive compounds from food can infl uence and help in modifying the gut microbiota composition, especially Firmicutes and Bacteroidetes. The purpose of this article is to discuss how signifi cant the role of nutrients and other bioactive compounds on Firmicutes and Bacteroidetes ratio in solving the obesity problem. This article was compiled based on the literature search in the last ten years, related to nutrients and bioactive compounds infl uence Firmicutes/Bacteroidetes ratio in obesity. The results from several literature searches provided evidence that alteration in gut microbiota composition was linked to the increase of body weight through metabolic pathways, which was characterized by the increasing number of Firmicutes, the decreased number of Bacteroidetes, and an increase in Firmicutes/Bacteroidetes ratio. The increasing number of Firmicutes could induce short-chain fatty acid (SCFA) production and lead to more energy harvesting. Several dietary factors from fi ber and amino acid, as well as bioactive compounds from an organic acid and polyphenol compounds, could infl uence the gut microbiota composition by reducing the Firmicutes level and increasing Bacteroidetes. The gut microbiota composition, especially Firmicutes and Bacteroidetes, could be induced by modifying diet enriched with fi ber, polyphenol compounds, and other specifi ed nutrients

Complementary feeding should be given to infants at 6 months in addition to breastmilk. Mothers’ knowledge and behavior in giving adequate complementary feeding are crucial to prevent malnutrition risk. During the pandemic, conventional nutrition education cannot be maintained and could lead to decreased mothers’ knowledge. This study is aimed at analyzing the effectiveness of nutrition education using online digital platforms (WhatsApp) to improve a mother’s behavior in providing nutritious complementary food based on the theory of planned behavior approach. This was a quasiexperiment with one pretest and posttest design group in the form of education and counselling. Ten educational sessions were developed to improve one or more TPB constructs. Media used for education are PowerPoint, text description, posters, and video tutorials; it is implemented by sending materials through the WhatsApp application. Using 80% power, the sample size was calculated for 155 subjects. Subjects were recruited through the accidental sampling method. Data was collected by the online method using a validated open-ended self-developed questionnaire for knowledge, while attitude, subjective norms, intention, and self-efficacy were measured using a Likert-scale questionnaire, where participants rated the strength of their belief that they could engage in a specific task. The paired -test was used to analyze the difference in outcomes measured. The response rate of this study was accounted for at 77.5%. The mean age of mothers was 28.2 years old; most of them were university graduates (80.2%) and working as private sector workers (40.0%). The average child’s age was 6.6 months old. 78.2% of children were exclusively breastfed. Our study revealed that 10 sessions of nutrition education and counselling covered over 8 days increased the mother’s knowledge ( vs. , respectively, before and after education; ) and resulted in psychological changes including mother’s attitude ( vs. ), subjective norm ( vs. ), perceived behavioral control ( vs. ), self-efficacy ( vs. ), and intention toward giving nutritious complementary feeding ( vs.