Fungi have been widely used in the food and medical fields for humans for a long time, and have even become a part of dietary culture. They may become the key to alleviating global “hidden hunger.” Australian scientists have discovered that applying a beneficial fungus to certain varieties of wheat used for bread production can result in the grains accumulating more trace nutrients that are beneficial for human absorption.
Wheat is the world’s second largest food crop, providing calories and nutrition for many people globally. However, many individuals suffer from “hidden hunger” due to a lack of trace elements such as iron and zinc, leading to micronutrient deficiencies. This condition poses a serious threat to public health, causing many to suffer illness or even death.
In the past, scientists have attempted to enhance wheat’s absorption of trace elements like zinc and iron by inoculating with arbuscular mycorrhizal (AM) fungi. However, the increase in phytic acid content as a side effect has hindered the human digestive system’s absorption of nutrients like zinc and iron.
In order to address this issue, scientists at the University of Adelaide in Australia sought a solution. They planted arbuscular mycorrhizal fungi in common wheat varieties in Australia, used for bread production, and unexpectedly found that the fungi not only increased the size of the grains but also enhanced the accumulation of essential micronutrients within the grains for human consumption.
This result indicates that cultivating wheat using this method can provide higher nutritional value for humans. The research findings were published in the “Plants, Humans, and Earth” journal on July 23.
The subject of the study was a fungus called “Rhizophagus irreparableis,” which forms beneficial symbiotic relationships with the roots of various plants, including barley, rice, sorghum, and wheat. The fungus extends through a network of slender hyphae into the soil, aiding plants in nutrient absorption while enhancing their resilience and reducing reliance on chemical fertilizers.
Due to these reasons, this fungus has become a prominent fungal species in the field of agricultural ecology and one of the most widely studied and applied fungi.
Researchers selected eight common varieties of bread wheat in Australia, separating them into groups with and without fungal inoculation, and planted them in low-phosphorus and high-phosphorus soils simulating impoverished and fertilized farmlands. After harvesting, they used advanced techniques such as X-ray fluorescence microscopy to analyze grain yield, nutritional components, phytic acid content, and distribution of trace elements within the grains.
The experimental results confirmed the team’s optimistic expectations. They found that wheat inoculated with AM fungi and grown in appropriately phosphorus-concentrated soil exhibited increased grain size, phosphorus, and zinc content, with a decrease in phytic acid levels. In fact, some wheat varieties inoculated with fungi showed even lower phytic acid content under high-phosphorus conditions compared to the control group.
As most plant phosphorus is stored in grains in the form of phytic acid, which is an anti-nutrient compound that tightly binds minerals such as zinc and iron, reducing the bioavailability of these micronutrients in the human intestinal tract. “Bioavailability” refers to the proportion of nutrients that can be actually absorbed and utilized by the human body or organisms.
Researchers also found that wheat inoculated with AM fungi showed increases in zinc and iron content in the endosperm layer, indicating improved bioavailability of these elements. The endosperm is a part of the grain bran rich in nutrients and typically retained in whole wheat flour as a vital component.
The researchers stated that this discovery signifies that this method can enhance wheat nutrition without sacrificing absorption rates. Adding fungal cultivation to bread wheat could potentially be a promising strategy that may produce wheat grains with higher micronutrient content and bioavailability, without affecting agricultural practices (such as phosphorus fertilization) or yield targets, ultimately helping alleviate the global issue of micronutrient deficiencies.
“This research demonstrates a sustainable option for better utilizing existing nutrients in soil. Through inoculating wheat with mycorrhizal fungi, we can enable wheat to provide essential micronutrients for humans,” said Dr. Stephanie J. Watts-Williams, the corresponding author of the study and project lead at the University of Adelaide.
Dr. Watts-Williams added, “Currently, approximately 30% of the global population suffers from zinc deficiency, and 60% from iron deficiency, which can harm human health. Zinc deficiency can impact normal development during pregnancy, childhood, and adolescence, and may lead to symptoms such as diarrhea; iron deficiency can cause anemia, affecting immune function and cognitive development, and in severe cases, can increase maternal and infant mortality.”
Lead author Dr. Thi Diem Nguyen from the University of Adelaide concluded, “We found that under low-phosphorus conditions, fungal inoculation does not affect phytic acid content in grains and may even reduce phytic acid in certain wheat varieties under high-phosphorus conditions, subsequently increasing the bioavailability of zinc and iron. These results show that applying phosphorus fertilization and inoculating beneficial fungi can be carried out in parallel, balancing grain yield and nutritional quality.”