New evidence on the superiority of insect-based animal feeds

icipe present findings that black soldier fly based meals increase beneficial bacteria in the gut of poultry, thus promoting health and growth of poultry, and pre-empting over-reliance on antibiotics

Since 2014, the International Centre of Insect Physiology and Ecology (icipe), has led the way in incorporating insects as alternative, more affordable, nutritious and sustainable protein options in animal feed. In particular, the Centre has demonstrated that black soldier fly larvae or the proteins derived from them, can be used safely as components in feeds for poultry, pigs and fish. In poultry, such feeds have been proven to improve growth performance, the quality and quantity of meat and eggs, and overall profitability for farmers.

In a study published recently in Scientific Reports journal (paper link), icipe researchers show that the incorporation of black soldier fly larvae in poultry feeds also increases the wealth of beneficial bacteria in the gut of poultry, thus promoting the overall health and growth of the birds.

Also known as friendly bacteria, this community of microorganisms is vital in strengthening the immunity, physical fitness and nutritional development of poultry. The beneficial bacteria form a protective barrier that lines the gut, preventing the growth of harmful bacteria such as Salmonella, Campylobacter and Clostridium perfringens, which are among the leading causes of foodborne diseases worldwide. They also influence the development of poultry by enabling fermentation of the plant fibres that the birds would otherwise be unable to digest, which boosts the release and absorption of nutrients.

Lactic acid bacteria

The icipe scientists note that three lactic acid bacteria, Lactobacillus, Enterococcus and Bacteroides, predominate the enhanced beneficial bacteria community that arises when poultry are fed on black soldier fly larvae based meals.

“Lactic acid bacteria are reputed for their role in the fermentation of carbohydrates to produce two types of acids; lactic and acetic, which help to create balance in the gut and stimulate growth of beneficial microbes. These bacteria also produce compounds known as bacteriocins, which prevent the development of disease causing agents in poultry,” observes Dr Fathiya Khamis, icipe Senior Scientist and lead author of the study.

These findings by icipe are significant against the ongoing quest, in Africa and globally, to re-evaluate and reduce the use of antibiotics in poultry farming. While the use of antibiotics to enhance growth or manage diseases in poultry has largely been useful, there are concerns about the rising resistance to antibiotics by harmful bacteria in poultry. Beyond the threat to the birds, this scenario also has adverse implications for human health. The resistant bacteria, or the detrimental residues from the antibiotics, could be transferred to people through poultry products such as eggs and meats. Thus, many countries have introduced bans or severe restrictions on the use of antibiotics in poultry, warranting the search for alternatives.

One of the most effective ways of producing healthy poultry without over-relying on antibiotics is by maintaining optimum gut health in the birds. This depends on various aspects, including the delicate balance between poultry, their cells and those of the bacteria, the intestinal environment, and how the poultry are managed.

“The most significant factor that influences the composition of the gut microorganisms in poultry is diet type and feed quality. Our research has demonstrated that insect-based poultry feeds can increase the abundance, diversity and composition of beneficial bacteria,” says Ms Evalyne Ndotono a Kenyan scholar who conducted the research as part of her MSc studies at icipe, while registered at Jomo Kenyatta University of Agriculture and Technology (JKUAT), Kenya.

Probiotics and prebiotics

Other options to the use of antibiotics in poultry production include reshaping the gut microbiota through the administration of probiotics and prebiotics. Probiotics are supplements made from strains of beneficial microorganisms such as bacteria and yeast, which can improve or maintain the good bacteria diversity in poultry. Prebiotics are nutritional compounds found in foods (typically high-fibre foods) that can induce the growth or activity of the beneficial microorganisms in poultry.

“Of the three lactic acid bacteria that we identified, the Lactobacillus species has the most potential as a probiotic candidate. Future studies could focus on extracting cultures of these bacteria from poultry, identifying the effective strains, and establishing ways through which they can be developed into probiotic products,” explains Dr Khamis.

In addition, the lactic acid bacteria break down the non-digestible carbohydrates to produce compounds such as lactose and sucrose, which are raw materials for prebiotics. The Lactobacillus bacteria species also have numerous health benefits for people. They are known to stimulate immune responses, to have anti-cancer activity, and to prevent and contribute to the treatment of inflammatory diseases. They also help to alleviate lactose intolerance, and to fight resistant pathogens and respiratory viral infections. Globally, there is a continued search for new strains of these bacteria. Thus, poultry may present new sources from which to isolate them.

Momentum for insect-based enterprises

“This research is part of icipe’s ongoing efforts to harness the potential of insects in the transformation of the current food system into a more sustainable and vibrant circular economy,” notes Dr Segenet Kelemu, icipe Director General & CEO.

She adds: “In regard to black soldier fly, in addition to its animal feed benefits, our research has demonstrated the insect’s utility in organic waste recycling to produce high quality, nutrient rich fertilisers that improve soil health and crop yield, and in the development of pest control products.”

The study provides further momentum for insect-based enterprises, building on the firm base laid by icipe and partners. This includes establishment of cost-effective insect rearing, harvesting and post-harvest techniques, which have been adopted effectively by smallholder and medium scale producers in East Africa. These efforts have been supported by a wide network of partnerships, massive capacity and awareness building, as well as the development of policies and national standards, and creation of marketing linkages, for insect products, including those from black soldier flies, in East Africa. There is also rising acceptance among consumers for products, like eggs and meat, produced using insect-based feeds. Moreover, evidence shows that insect-based enterprises can be undertaken with minimal inputs. Therefore, they are ideal for women, young farmers and low-income households, who are often constrained by limited access to agricultural resources.

Notes for Editors

Research details: Ndotono, E.W., Khamis, F.M., Bargul, J.L. et al. Gut microbiota shift in layer pullets fed on black soldier fly larvae-based feeds towards enhancing healthy gut microbial community. Sci Rep 12, 16714 (2022).

Corresponding author: Fathiya M. Khamis;

Funding: We acknowledge financial support from the Norwegian Agency for Development (Norad) through the Combating Arthropod Pests for Better Health, Food and Resilience to Climate Change (CAP-Africa) Grant No. RAF-3058 KEN-18/0005; Netherlands Organization for Scientific Research, WOTRO Science for Global Development (NWO-WOTRO) (ILIPA—W 08.250.202), the Canadian International Development Research Centre (IDRC) and the Australian Centre for International Agricultural Research (ACIAR) (INSFEED—Phase 2: Cultivate Grant No: 108866-001), and Rockefeller Foundation (SiPFeed—Grant No: 2018 FOD 009) and the Curt Bergfors Foundation Food Planet Prize Award to icipe. We gratefully acknowledge the icipe core donors: Swedish International Development Cooperation Agency (Sida); Swiss Agency for Development and Cooperation (SDC), Federal Democratic Republic of Ethiopia and Government of the Republic of Kenya. The views expressed herein do not necessarily reflect the official opinion of the donors.

The International Centre of Insect Physiology and Ecology ( headquartered in Nairobi, Kenya, is the only research institution in Africa working primarily on insects and other arthropods. The Centre conducts world-class science, and then translates this knowledge into innovate environmentally friendly, affordable, accessible and easy to use solutions to tackle crop pests and disease vectors. icipe’s role also extends to the conservation and sustainable exploitation of the beneficial insect biodiversity. Thus, icipe works through the 4Hs Themes – Human Health, Animal Health, Plant Health and Environmental Health – a holistic and integrated framework that has sustainable development as its basis, to improve food security, health and the overall well-being of communities in Africa. We gratefully acknowledge the support of icipe core donors: Swedish International Development Cooperation Agency (Sida); Swiss Agency for Development and Cooperation (SDC), Federal Democratic Republic of Ethiopia and Government of the Republic of Kenya. The views expressed herein do not necessarily reflect the official opinion of the donors.