Could bacteria hold the secret to delaying death? Magnetic microbes extended worm lifespan by more than 43% in a new ageing study

Suppose the secret of preventing ageing lies within bacteria which can produce mini-magnetic structures within themselves.

This is the bizarre idea proposed by an interesting discovery by scientists from the Hefei Institutes of Physical Science, Chinese Academy of Sciences. In the tests conducted on the nematode Caenorhabditis elegans, the scientists observed an increase of 43.39% in the longevity of worms when exposed to the bacteria which produce magnets.

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The effect was not limited to survival.

Treated worms also showed better preservation of neurological function and intestinal health as they aged.

It turns out that the researchers attribute many of their results to a phenomenon referred to as ferroptosis, which is a type of programmed cell death linked to increased levels of iron and oxidative damage of lipids.

According to the researchers' claims, this particular strain of bacteria (Magnetospirillum magneticum AMB-1 or AMB-1) might affect the rate of ageing in organisms, since it seems to prevent the formation of some of the molecular mechanisms behind such cell damage.

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The research, which was published in Free Radical Biology and Medicine, did not prove the hypothesis that magnetic bacteria are capable of prolonging human life. All the experiments have been carried out on C. elegans – a model organism often used in ageing studies.

Nevertheless, the results provide scientists with yet another direction of investigation.

A bacterium with a built-in magnetic system

AMB-1 is one of the magnetotactic bacteria that differs from other bacteria in the way they orient themselves along magnetic lines. This is due to the development of magnetosomes, which are special magnetic structures.

Such a unique structure has attracted a lot of attention for the purpose of targeted drug delivery and cancer studies but has remained rather unnoticed in terms of its impact on the ageing process.

Chinese researchers headed by Prof. An Xu intended to study the effect of AMB-1 on the ageing of C. elegans.

The worms are very convenient in this type of research because of their short life span and numerous pathways related to ageing that can be studied in this organism.

When worms were exposed to the treatment with AMB-1, it turned out that there was a significant difference in their longevity, as the average lifespan of treated worms was increased by 43.39% in comparison with that of the control group.

However, this is not all that the researchers wanted to find out about the treated worms.

Their experiments indicated that AMB-1 helped maintain neurological performance and intestinal integrity in older worms.

That distinction is important in ageing research. Extending lifespan and extending the period of healthy function are not necessarily the same thing.

The surprising role of iron in the ageing process

The researchers then looked for a biological explanation for the effect.

One clue came from iron.

The presence of iron in the cells is vital due to its involvement in biological functions like metabolism and oxygen transportation. However, excessive amounts of unregulated iron may cause oxidative stress and chemical reactions that harm lipids, which are fatty compounds forming cellular membranes.

That type of damage is closely connected to ferroptosis.

Ferroptosis is different from more familiar forms of programmed cell death. It is highly correlated with the oxidation of lipids mediated by iron and has been an active field of research in areas as diverse as oncology and neurodegeneration.

In the experiments on worms, administration of AMB-1 was correlated with low amounts of iron and lipid peroxidation.

These observations led the scientists to ferroptosis as a possible mechanism connecting the two.

Genetic experiments provided additional clues. The researchers identified several ferroptosis-related pathways involving genes including ftn-1, bli-3 and ads-1 that appeared to participate in the lifespan effects associated with AMB-1.

These results imply that the effects of the bacteria are not limited to a general boost of the overall health condition but rather are connected with the interaction between the bacteria and cell functions concerning iron metabolism, oxidative stress, and ferroptosis.

Why the magnetosomes appear to matter

One of the more intriguing parts of the research was the comparison between different forms of the bacterium.

The team wanted to know whether AMB-1’s magnetic machinery itself contributed to the biological effect.

They compared normal AMB-1 with bacterial variants that could no longer produce magnetosomes or had altered magnetic properties.

The results pointed towards magnetosome production as an important part of the lifespan-extending effect.

The wild-type AMB-1 had a greater effect compared to the reversibly non-magnetotactic strain RNM-AMB-1. The strain NM-AMB-1 did not have a similar effect on lifespan.

That comparison gives the study a more specific biological question to pursue. If magnetosome production is connected to the effect, researchers will need to determine how those structures ultimately influence the worm's internal environment.

The current experiments do not establish the complete chain of events.

The question is still open as to how precisely the bacterial magnetosomes affect the physiology of the worms and whether changes in iron homeostasis caused by bacteria can be recapitulated in other animals.

This would become a significant issue for the results to apply to human ageing.

What the study means for anti-ageing research

What makes the study interesting is the very fact that instead of using the typical medication or genetically manipulating the organism, the scientists came across the microbe, which biology can possibly affect the pathways involved in the process of ageing.

This work is another example of increasing the interest towards the interaction between microbes and host organisms. It is known that microorganisms can influence metabolism, immune system function and other physiological processes of animals; however, the mechanisms differ greatly depending on the organism and the experiment.

In this case, AMB-1 is not yet a potential medicine against ageing but rather a research material and a possible biological source.

The increased life expectancy of worms by 43.39% cannot be extrapolated to humans. C. elegans is just a simple model organism, and any changes made to it to make a particular intervention have to be tested several times before it can be considered applicable to mammalian species.

Thus, scientists state that their work shows how a new microbial approach to studying healthy ageing can be developed.

.The most interesting question may therefore not be whether magnetic bacteria can make humans live longer.

It is whether studying these microbes can reveal new ways of controlling ferroptosis, iron accumulation and oxidative damage — processes that are also being investigated in connection with several age-related diseases.

If further research can pinpoint the way that AMB-1 affects the system, then there is great potential for using AMB-1 as an aid in the study of such processes.

Currently, this fascinating bacterium has done one thing in particular in the laboratory worm, which is to provide yet another avenue for exploring the connection between bacteria, iron and ageing biology.

FAQ

1. Are worms really made to live 43% longer with the help of magnetic bacteria?

It can be stated that the worms which were treated with Magnetospirillum magneticum AMB-1 lived longer by 43.39%. The study was carried out in C. elegans, not in humans.

2. What is ferroptosis?

Ferroptosis is one type of programmed cell death linked with oxidation of lipids in the presence of iron ions. This process is studied to play a role in many physiological phenomena, among which there are aging and disease.

3. What made magnetosomes important in the research?

Magnetosomes are special magnetic particles produced by magnetotactic bacteria. As per the experiments, it was thought that one of the reasons for increasing the lifespan of worms was the formation of magnetosomes.

4. Can magnetic bacteria be used to increase human lifespan?

At the moment, there is no proof that AMB-1 is capable of extending human lifespan. The study was carried out in C. elegans, and a lot more studies will be needed to prove that such mechanism works in mammals.