Bioengineers Current Journal and Paper in Review

Vol. 8

Synbiotic Fermented Milk with Double Fortification (Fe-Zn) as a Strategy to Address Stunting

A Review by the Journalism Division of SBE UISC 2021

Based on the article Synbiotic Fermented Milk with Double Fortification as a Strategy to Address Stunting: A Randomized Controlled Trial among Children Under Five in Yogyakarta, Indonesia by Helmyati, S., Shanti, K. M., Sari, F. T., Sari, M. P., Atmaka, D. R.,  Pratama, R. A., Wigati, M., Wisnusanti, S. U., Nisa, F. Z., and Rahayu, E. S. from the Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta

Published in Advances in Microbial Fermentation Processes on 19th March 2021 (

This review is made to support our upcoming event SBEWARE, which focuses on raising awareness of health education and children’s malnutrition in Indonesia. As a part of this event, you can participate in improving Indonesian children's health quality by giving a donation via


According to the World Health Organization (WHO), stunting is the impaired growth and development that children experience from poor nutrition, repeated infection, and inadequate psychosocial stimulation. Stunting usually occurs in developing countries, including Indonesia. Therefore, a team from the University of Gadjah Mada conducted a study about how synbiotic fermented milk with double fortification of iron and zinc might be the solution for this problem. Iron and zinc are crucial for human growth, and to balance the gut’s microbiota, synbiotic food, such as fermented milk, is present.

The clinical trial for this study involved 81 children aged 2-5 years old and categorized as stunted based on height-for-age (HAZ) z-score in Seyegan District, Yogyakarta Province, Indonesia. The subjects of the study are divided into two groups, intervention—the subjects who are given the synbiotic milk with fortification—and control—the subjects who are given the same milk, but without the fortification. The synbiotic fermented milk was given to the intervention group every day for three months. In the end, they found that the growth in the intervention group was higher than the control group; however, the results were not significantly different. Hence, the success of the double fortification method still remains questionable, which could be caused by the limitations that the experiment had, like lack of duration and limited study group.

Highlighted Topics:

Food Fortification

  • Food fortification is a method to add vitamins and minerals into consumed foods to increase their nutrients

  • Food fortification is cost-effective, costing between USD 1 and USD 134 per disability-adjusted-life-year.

  • In this study, the fortified micronutrients were zinc and iron. Both micronutrients are crucial for human growth. However, higher iron intake comes with many side effects, such as diarrhea, increasing pathogens, and inflammatory diseases. The presence of synbiotic food, like fermented milk, is needed to ameliorate said side effects due to its ability to balance the gut’s microbiota and reduce the utilization by pathogenic bacteria. 

Subjects and Design of the Study

  • The clinical trial was conducted on 81 children aged 2-5 years old and categorized as stunted based on height-for-age (HAZ) z-score in Seyegan District, Yogyakarta Province, Indonesia. 

  • The subjects were divided into two groups: intervention and control. The intervention group is the ones who were given the synbiotic milk. The control group was given the same milk, only without fortification.

  • The main parts of the study contain screening, intervention, and follow-up phase. 

  • All data were analyzed with STATA 13 by using several tests including the chi-squared test or Fisher's exact test, Shapiro-Wilk test, and multiple linear regression to determine the subject's nutritional status. 

Production of Fortification Milk

  • The ingredients used were skim milk, sugar, probiotic Lactobacillus plantarum (L. plantarum), prebiotic fructooligosaccharides (FOS), iron fortificant, and zinc fortificant. Both fortificant were produced in the USA, while the skim milk, probiotic and prebiotic were obtained from Indonesia. 

  • Skim milk is preferred over whole milk and ultra-high-temperature milk because it has a better consistency, sensory characteristics, lower price, and positive correlation to probiotic viability and fermented milk flavor. 

  • Steps:

    • Dissolve sugar, skim milk, and then FOS and fortificants to water.

    • Sterilization 

    • Inoculation of L. plantarum 

    • Incubation

  • All subjects were given deworming medication to minimize worm infection potential.

  • The synbiotic fermented milk was given to the subjects every day for three months 

  • A bottle of synbiotic fermented milk with double fortification contained 79.93 kcal energy, 2.26 g protein, 1.95 g fat, 13.67 g carbohydrate, 1.27 g crude fiber, 90 mg calcium, 2.26 mg iron, 1.22 mg zinc, and 3.23 × 108 CFU/mL L. plantarum 

  • A bottle of synbiotic milk without fortification contained 85.75 kcal energy, 2.05 g protein, 1.51 g fat, 16.44 g carbohydrate, 0.74 g crude fiber, 88 mg calcium, 0.73 mg iron, 0.18 mg zinc, and 3.19 × 108 CFU/mL L. plantarum


Results From Testing
  • After three months, from all 38 subjects of the intervention group that were first categorized as stunted in the preliminary phase, nine were categorized as normal.

  • The body weight in the subject intervention growth increased by 0.7 kg while height increased by 2.58 cm. The weight and height gained by the control group were 0.6 kg and 2.5 cm. 

  • Based on the WHO Child Growth Standards, the increase in body weight and height of children aged 2–5 years over the course of three months ranged from 0.5 to 0.6 kg and 1.5 to 2.5 cm, respectively. This shows that growth in both groups that consume synbiotic is significantly more than children who were given normal milk. 


Even though there are several successes shown, these results are still not enough to be categorized as a successful experiment. The experiments conducted still have several limitations such as:

  • Lack of duration: three months is still difficult to conclude whether the effect of the intervention will continue.

  • Limited study group: the intervention and control groups are both given synbiotic milk, with the only difference being the iron and zinc fortificant presence. This left the researchers without an exact conclusion on whether symbiotic milk is truly more beneficial to growth than regular milk.

Additional Readings: 

Putri, F. and Qomariyah, N. 2020. ‘Factors Associated to Stunting in Children Aged 6-24 Months in Yogyakarta’. Jurnal Cakrawala Promkes. 2 (1). Available at:


Markowiak, P., & Śliżewska, K. 2017. ‘Effects of Probiotics, Prebiotics, and Synbiotics on Human Health’. Nutrients, 9(9), 1021. Available at:

Olson, Rebecca et al. 202. 'Food Fortification: The Advantages, Disadvantages and Lessons from Sight and Life Programs'. Nutrients. 13(4). Available at:

World Health Organization. 2015. ‘Stunting in a Nutshell’. Available at: